• Food Science and Biotechnology
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• 제14권6호
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• pp.860-865
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• 2005

A gene for a putative glucoamylase, stg, of a hyperthermophilic archae on Sulfolobus tokodaii was cloned and expressed in Escherichia coli. The recombinant glucoamylase (STGA) had an optimal temperature of $80^{\circ}C$ and was extremely thermostable with a D-value of 17 hr. The pH optimum of the enzyme was 4.5. Being different from fungal glucoamylases, STGA hydrolyzed maltotriose (G3) most efficiently. Gel permeation chromatography and sedimentation equilibrium analytical ultracentrifugation analysis showed that the enzyme existed as a dimer. STGA was stable enough to hydrolyze liquefied com starch to glucose in 4 hr at $90^{\circ}C$ with a yield of95%. Comparison of the $k_{cat}$ values for the hydrolysis and the reverse reaction at $75^{\circ}C$ and $90^{\circ}C$ indicated that glucose production by STGA was more efficient at $90^{\circ}C$ than $75^{\circ}C$. Therefore, STGA showed great potential for application to the industrial glucose production process due to its high thermostability.

• Journal of Ginseng Research
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• 제40권4호
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• pp.382-394
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• 2016

Background: Ginsenosides are the characteristic and principal components which manifest a variety of the biological and pharmacological activities of the roots and rhizomes of Panax ginseng (GRR). This study was carried out to qualitatively and quantitatively determine the ginsenosides in the cultivated and forest GRR. Methods: A rapid and sensitive ultra-high-performance liquid chromatography coupled with diode-array detector and quadrupole/time of flight tandem mass spectrometry (UPLC-DAD-QTOF-MS/MS) was applied to the qualitative analysis of ginsenosides and a 4000 QTRAP triple quadrupole tandem mass spectrometer (HPLC-ESI-MS) was applied to quantitative analysis of 19 ginsenosides. Results: In the qualitative analysis, all ingredients were separated in 10 min. A total of 131 ginsenosides were detected in cultivated and forest GRR. The method for the quantitative determination was validated for linearity, precision, and limits of detection and quantification. 19 representative ginsenosides were quantitated. The total content of all 19 ginsenosides in the forest GRR were much higher than those in the cultivated GRR, and were increased with the growing ages. Conclusion: This newly developed analysis method could be applied to the quality assessment of GRR as well as the distinction between cultivated and forest GRR.

• 대기
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• 제24권2호
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• pp.245-251
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• 2014

Statistical trajectory analysis has been widely used to identify potential source regions for chemically and radiatively important chemical species in the atmosphere. The most widely used method is a statistical source-receptor model developed by Stohl (1996), of which the underlying principle is that elevated concentrations at an observation site are proportionally related to both the average concentrations on a specific grid cell where the observed air mass has been passing over and the residence time staying over that grid cell. Thus, the method can compute a residence-time-weighted mean concentration for each grid cell by superimposing the back trajectory domain on the grid matrix. The concentration on a grid cell could be used as a proxy for potential source strength of corresponding species. This technical note describes the statistical trajectory approach and introduces its application to estimate potential source regions of $CO_2$ enhancements observed at Korean Global Atmosphere Watch Observatory in Anmyeon-do. Back trajectories are calculated using HYSPLIT 4 model based on wind fields provided by NCEP GDAS. The identified $CO_2$ potential source regions responsible for the pollution events observed at Anmyeon-do in 2010 were mainly Beijing area and the Northern China where Haerbin, Shenyang and Changchun mega cities are located. This is consistent with bottom-up emission information. In spite of inherent uncertainties of this method in estimating sharp spatial gradients within the vicinity of the emission hot spots, this study suggests that the statistical trajectory analysis can be a useful tool for identifying anthropogenic potential source regions for major GHGs.

• 한국항만경제학회지
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• 제35권3호
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• pp.125-150
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• 2019

훈춘지역은 지린성의 대외 개방 문호 및 창-지-투 지역의 유일한 개발개방선도구로 지역 물류의 발전에 중요한 거점 지역으로써 훈춘지역의 물류경쟁력을 촉진시키는 것은 동북지역 경제발전을 촉진시키는데는 중요한 요인이라고 할 수 있다. 이에 본 연구는 SWOT분석을 적용하여 훈춘지역의 물류경쟁력 활성화 요인을 도출하고, 중국과 한국물류전문가를 대상으로 AHP 설문조사를 통해 훈춘지역 물류경쟁력 활성화 요인의 우선순위를 도출함으로써 정책결정자에게 제시하는데 그 목적이 있다. 분석결과, 기회요인, 강점요인 순으로 가중치가 높게 나타났으며, 일대일로 정책 촉진 및 확대, 국가정책을 통한 적극적 지원, 국제물류센터도시의 건설, 물류중심지 건설, 대량화물 공급지 등의 요인 순으로 우선순위가 높게 제시되었다. 마지막으로, 종합적 관점에서 본 연구는 훈춘지역의 물류경쟁력 강화전략을 위해 훈춘지역이 가진 강점을 중심으로 한 SO전략(강점-기회전략)과 ST전략(강점-위협전략) 등 정책적 시사점을 제시하였다.

• Molecules and Cells
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• 제39권4호
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• pp.345-351
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• 2016

Wound healing is a complex physiological process necessitating the coordinated action of various cell types, signals and microRNAs (miRNAs). However, little is known regarding the role of miRNAs in mediating this process. In the present study, we show that let-7c miRNA is decreased in heat-denatured fibroblasts and that inhibiting let-7c expression leads to the increased proliferation and migration of dermal fibroblasts, whereas the overexpression of let-7c exerts an opposite effect. Further investigation has identified heat shock protein 70 as a direct target of let-7c and has demonstrated that the expression of HSP70 in fibroblasts is negatively correlated with let-7c levels. Moreover, down-regulation of let-7c expression is accompanied by up-regulation of Bcl-2 expression and down-regulation of Bax expression, both of which are the downstream genes of HSP70. Notably, the knockdown of HSP70 by HSP70 siRNA apparently abrogates the stimulatory effect of let-7c inhibitor on heat-denatured fibroblasts proliferation and migration. Overall, we have identified let-7c as a key regulator that inhibits fibroblasts proliferation and migration during wound healing.

• Mycobiology
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• 제48권5호
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• pp.427-430
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• 2020

Ganoderma lingzhi is a well-known source of natural fungal medicines which has been given for the treatment of several diseases. China is one of the major commercial producers of Ganoderma mushroom worldwide. However, with the expansion of the commercial cultivation, the occurrence of the fungal diseases on G. lingzhi has also been increased. The green mold disease symptoms were observed in the cultivation base of G. lingzhi in Zuojia Town, Jilin City, Jilin Province, China, causing the basidiomes to be rotten and withered, and the green mycelium layer generated gradually. The pathogenicity tests showed the same symptoms as appeared naturally in Zuojia mushroom base. Morphology characters revealed conidia green, ellipsoid, globose, 2.56-4.83 × 2.09-4.22 ㎛, length-width ratio was 1.1-1.2 (n = 10). Conidiophores trichoderma-like, often asymmetry, branches solitary, paired or in whorls of 3 phialides formed solitary, paired or in whorl, variable in shape, lageniform, sometimes ampulliform or subulate. While using molecular methodology, comparing with the sequences of Trichoderma hengshanicum from GenBank, the analyzed sequence showed 97.32% homology with the RPB2 sequences, 100% with the TEF1-a sequences. A fungus isolated from the diseased tissues was identified based on morphology and molecular studies as T. hengshanicum. This is the first report of T. hengshanicum causing the green mold disease of G. lingzhi in China.

• 한국수학교육학회지시리즈B:순수및응용수학
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• 제16권4호
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• pp.327-344
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• 2009

In this paper, we deal with the following system of nonlinear singular boundary value problems(BVPs) on time scale $\mathbb{T}$ $$\{{{{{{x^{\bigtriangleup\bigtriangleup}(t)+f(t,\;y(t))=0,\;t{\in}(a,\;b)_{\mathbb{T}},}\atop{y^{\bigtriangleup\bigtriangleup}(t)+g(t,\;x(t))=0,\;t{\in}(a,\;b)_{\mathbb{T}},}}\atop{\alpha_1x(a)-\beta_1x^{\bigtriangleup}(a)=\gamma_1x(\sigma(b))+\delta_1x^{\bigtriangleup}(\sigma(b))=0,}}\atop{\alpha_2y(a)-\beta_2y^{\bigtriangleup}(a)=\gamma_2y(\sigma(b))+\delta_2y^{\bigtriangleup}(\sigma(b))=0,}}$$ where $\alpha_i$, $\beta_i$, $\gamma_i\;{\geq}\;0$ and $\rho_i=\alpha_i\gamma_i(\sigma(b)-a)+\alpha_i\delta_i+\gamma_i\beta_i$ > 0(i = 1, 2), f(t, y) may be singular at t = a, y = 0, and g(t, x) may be singular at t = a. The arguments are based upon a fixed-point theorem for mappings that are decreasing with respect to a cone. We also obtain the analogous existence results for the related nonlinear systems $x^{\bigtriangledown\bigtriangledown}(t)$ + f(t, y(t)) = 0, $y^{\bigtriangledown\bigtriangledown}(t)$ + g(t, x(t)) = 0, $x^{\bigtriangleup\bigtriangledown}(t)$ + f(t, y(t)) = 0, $y^{\bigtriangleup\bigtriangledown}(t)$ + g(t, x(t)) = 0, and $x^{\bigtriangledown\bigtriangleup}(t)$ + f(t, y(t)) = 0, $y^{\bigtriangledown\bigtriangleup}(t)$ + g(t, x(t)) = 0 satisfying similar boundary conditions.

• Journal of Microbiology and Biotechnology
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• 제31권8호
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• pp.1134-1143
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• 2021

In the present study, we investigated the inhibitory effect of heat-killed Enterococcus faecalis (E. faecalis) and live E. faecalis on benign prostatic hyperplasia (BPH). The BPH rat model was established by administering male rats with testosterone propionate (TP, 5 mg/kg, in corn oil) via subcutaneous injections daily for four weeks after castration. The rats were divided into five groups: Con, corn oil-injected (s.c.) + DW administration; BPH, TP (5 mg/kg, s.c.) + DW administration; BPH+K_EF, TP (5 mg/kg, s.c.) + heat-killed E. faecalis (7.5 × 10¹² CFU/g, 2.21 mg/kg) administration; BPH+L_EF, TP (5 mg/kg, s.c.) + live E. faecalis (1 × 10¹¹ CFU/g, 166 mg/kg) administration; BPH+Fi, TP (5 mg/kg, s.c.) + finasteride (1 mg/kg) administration. In both of BPH+K_EF and BPH+L_EF groups, the prostate weight decreased and histological changes due to TP treatment recovered to the level of the Con group. Both of these groups also showed regulation of androgen-signaling factors, growth factors, and apoptosis-related factors in prostate tissue. E. faecalis exhibited an inhibitory effect on benign prostatic hyperplasia, and even heat-killed E. faecalis showed similar efficacy on the live cells in the BPH rat model. As the first investigation into the effect of heat-killed and live E. faecalis on BPH, our study suggests that heat-killed E. faecalis might be a food additive candidate for use in various foods, regardless of heat processing.

• Asian-Australasian Journal of Animal Sciences
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• 제31권12호
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• pp.1974-1979
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• 2018

Objective: This study compared fatty acid compositions and antioxidant activities of high-preference cuts (loin, tenderloin, and rib) and low-preference cuts (brisket, topside, and shank) of Hanwoo (Bos taurus coreanae) cows to obtain potentially useful information for promoting the consumption of various low-preference cuts. Methods: Individual 500 g samples of fresh beef were collected from each of the six cuts from 10 Hanwoo cows (quality grade 1) and immediately freeze-dried. The dried samples were evaluated for fatty acid composition, free radical scavenging activities (hydroxyl, alkyl, and 2, 2'-diphenyl-1-picrylhydrazyl [DPPH] radical), and antioxidative enzyme activities (glutathione peroxidase [GPx], glutathione-S-transferase [GST], and superoxide dismutase [SOD]). Results: The percentages of total polyunsaturated fatty acids were significantly higher in low-preference cuts than in high-preference cuts (p<0.05). Hydroxyl, alkyl, and DPPH radical scavenging activities were significantly higher in low-preference cuts than in high-preference cuts (p<0.05). In addition, the activities of antioxidant enzymes, such as GPx, GST, and SOD, were significantly higher in low-preference cuts compared with high-preference cuts (p<0.05). Conclusion: These results may influence consumers to include more low-preference cuts in their selections based on the nutritional facts, which could help to balance the beef market in South Korea.

• Journal of Gynecologic Oncology
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• 제29권6호
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• pp.99.1-99.11
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• 2018

Objective: The present study is to evaluate the biological functions of long non-coding RNA (lncRNA), X-inactive specific transcript, X-inactive specific transcript (XIST) in human epithelial ovarian cancer (EOC). Methods: XIST was upregulated in EOC cell lines, CAOV3 and OVCAR3 cells by lentiviral transduction. The effects of XIST overexpression on cancer cell proliferation, invasion, chemosensitivity and in vivo tumor growth were investigated, respectively. Possible sponging interaction between XIST and human microRNA hsa-miR-214-3p was further evaluated. Furthermore, hsa-miR-214-3p was overexpressed in XIST-upregulated CAOV3 and OVCAR3 cells to evaluate its effect on XIST-mediated EOC regulation. Results: Lentivirus-mediated XIST upregulation had significant anticancer effects in CAOV3 and OVCAR3 cells by suppressing cancer cell proliferation, invasion, increasing cisplatin chemosensitivity and inhibiting in vivo tumor growth. Hsa-miR-214-3p was confirmed to directly bind XIST, and inversely downregulated in XIST-upregulated EOC cells. In EOC cells with XIST upregulation, secondary lentiviral transduction successfully upregulated hsa-miR-214-3p expression. Subsequently, hsa-miR-214-3p upregulation functionally reversed the anticancer effects of XIST-upregulation in EOC. Conclusion: Upregulation of lncRNA XIST may suppress EOC development, possibly through sponging effect to induce hsa-miR-214-3p downregulation