• Journal of Ecology and Environment
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• v.46 no.2
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• pp.136-143
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• 2022

Background: In northern Thailand, the longan flower is the principal nectar source for honey production. Microorganisms play a critical function in the agricultural ecology. The morphological characteristics of fungal species found in longan pollen were studied. Aspergillus spp. were found to be invertase-producing strains and were employed in the longan syrup production process. The purpose of this study was to evaluate the effects of invertase-added longan syrup on the adult honey bee population numbers that were fed by this syrup for 16 weeks. Results: Different fungal species were found in longan pollen samples. Aspergillus was the main genus, with three predominant sections: Nigri, Flavi, and Terrei. Other isolated species were Trichoderma spp., Rhizopus spp., Neurospora spp., Chaetomium spp., Fusarium spp. and Penicillium spp. However, Aspergillus spp. is the only fungal species that produces the enzyme invertase. The invertase-producing strains belonging to the Aspergillus section Nigri were found to be A. niger LP5 with an optimum activity at pH 6.0 and 60℃. When A. niger LP5 invertase was used for longan syrup processing, the highest levels of glucose (3.45%) and fructose (2.08%) were found in invertase added longan syrup (C), while fresh (A) and boiled longan syrup (B) had lower contents of both sugars. The sucrose content was detected in (A) at 4.25%, while (B) and (C) were at 4.02% and 3.08%, respectively. An appropriate amount of sugar to feed and maintain the honey bee population was considered. The data showed no statistically significant differences between the two selected forms of longan syrup compared to the sugar syrup examined by the adult honey bee population. Conclusions: The main species of isolated fungi from longan pollen were Aspergillus spp. The discovery of an invertase-producing strain of A. niger LP5 has enabled its application for enzyme utilization in the invert sugar preparation process. The adult worker bee populations fed by longan syrup from both boiled and invertase-added sources showed an increasing trend. Artificial syrup made from longan fruit to feed honey bees when natural food sources are limited can be applied.

• Korean Journal of Pharmacognosy
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• v.24 no.2
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• pp.116-123
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• 1993

The genus Ganoderma is typical wood-rotting fungi and its fruiting body has been used as an important herb in oriental medicine. Recent research discovered antitumor components from Ganoderma lncidum. Various Ganoderma species are being cultivated in Korea. However, taxonomic system of the genus Ganoderma has been based mainly on the macromorphology of fruiting bodies and the ultrastructural characteristics of basidiospores. Since there are similar characteristics in Ganoderma mycelia grown on the same artificial media, it is suggested that the compatibility of the fungi by di-mon mating be used as an aid to determine the identity of species in addition to the conventional characterization. In this study, we examined physiological and genetical properties such as growth temperature, pH, compatibility and enzyme or protein patterns of laccase, esterase and cellular proteins of G. lucidum RZ, G. tsugae and Ganoderma species cultivated in Korea by electrophoresis for characterization of the isolates. We found that compatibility test and isozyme patterns of laccase and esterase of the mycelia could be used for the differentiation of the isolates. These results showed that Ganoderma species cultivated in Korea is genetically similar to G. lucidum but physiologically closer to G. tsugae than to G. lucidum.

• Journal of Microbiology and Biotechnology
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• v.15 no.5
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• pp.1125-1129
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• 2005

Cloning of a 6.6-kb BamHI digested chromosomal DNA from S. griseus IFO13350 revealed the presence of an additional gene encoding a novel trypsin-like enzyme, named SprU. The SprU protein shows a high homology ($79\%$ identity, $88\%$ similarity) with the SGT protease, which has been reported as a bacterial trypsin in the same strain. The amino acid sequence deduced from the nucleotide sequence of the sprU gene suggests that SprU is produced as a precursor consisting of an amino-terminal presequence (29 amino acid residues), prosequence (4 residues), and mature trypsin consisting of 222 amino acids with a molecular weight of 22.94 kDa and a calculated pI of 4.13. The serine, histidine, and aspartic acid residues composing the catalytic triad of typical serine proteases are also well conserved. When the trypsin activity of the SprU was spectrophotometrically measured by the enzymatic hydrolysis of the artificial chromogenic substrate, N-${alpha}$-benzoyl-DL-arginine-p-nitroanilide, the S. lividans transformant with pWHM3-U gave 3 times higher activity than that of control. When the same recombinant plasmid was introduced into S. griseus, however, the gene dosage effect was not so significant, as in the cases of other genes encoding serine proteases, such as sprA, sprB, and sprD. Although two trypsins, SprU and SGT, have a high degree of homology, the pI values, the gene dosage effect in S. griseus, and the gene arrangement adjacent to the two genes are very different, suggesting that the biochemical and biological function of the SprU might be quite different from that of the SGT.

• Reproductive and Developmental Biology
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• v.37 no.1
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• pp.29-33
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• 2013

The objective of this work was to analyze the concentrations of progesterone (P4) and estrogen (E2) hormones changed during estrus synchronization in dairy heifers. Estrus synchronization was carried out with CIDR$^{(R)}$ (Controlled Intravaginal Drug Release) devices. Corpus luteum (CL) was classified into three grades based on its size and palpable characteristics. The concentrations of P4 and E2 were measured by enzyme-amplified chemiluminescence. Serum P4 concentration was markedly low at the estrus stage (36 hrs after removal of CIDR) compared to other stages, while E2 concentration was kept high during estrus stage. The serum P4 concentration was highest in the CL classified into grade I. These results indicate that P4 concentration could be used as a criteria for determining recipients for artificial insemination or embryo transfer in dairy cattle.

• The Korean Journal of Physiology and Pharmacology
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• v.18 no.3
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• pp.249-254
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• 2014

The purpose of this study is to characterize the effects of KHG26792 (3-(naphthalen-2-yl(propoxy)methyl)azetidine hydrochloride), a potential skin whitening agent, on melanin synthesis and identify the underlying mechanism of action. Our data showed that KHG26792 significantly reduced melanin synthesis in a dose-dependent manner. Additionally, KHG26792 downregulated microphthalmia-associated transcription factor (MITF) and tyrosinase, the rate-limiting enzyme in melanogenesis, although tyrosinase was not inhibited directly. KHG26792 activated extracellular signal-regulated kinase (ERK), whereas an ERK pathway inhibitor, PD98059, rescued KHG26792-induced hypopigmentation. These results suggest that KHG26792 decreases melanin production via ERK activation. Moreover, the hypopigmentary effects of KHG26792 were confirmed in a pigmented skin equivalent model using Cervi cornus Colla (deer antler glue), in which the color of the pigmented artificial skin became lighter after treatment with KHG26792. In summary, our findings suggest that KHG26792 is a novel skin whitening agent.

• Journal of Korean Neurosurgical Society
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• v.58 no.2
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• pp.101-106
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• 2015

Objective : The aim of this study was to explore the immunity in rats transplanted with adipose-derived mesenchymal stem cells (ADSCs) and acellular nerve (ACN) for repairing sciatic nerve defects. Methods : ADSCs were isolated from the adipose tissues of Wistar rats. Sprague-Dawley rats were used to establish a sciatic nerve defect model and then divided into four groups, according to the following methods : Group A, allogenic nerve graft; Group B, allograft with ACN; Group C, allograft ADSCs+ACN, and Group D, nerve autograft. Results : At the day before transplantation and 3, 7, 14, and 28 days after transplantation, orbital venous blood of the Sprague-Dawley rats in each group was collected to detect the proportion of $CD3^+$, $CD4^+$, and $CD8^+$ subsets using flow cytometry and to determine the serum concentration of interleukin-2 (IL-2), tumor necrosis $factor-{\alpha}$ ($TNF-{\alpha}$) and $interferon-{\gamma}$ ($IFN-{\gamma}$) using enzyme-linked immunosorbent assay (ELISA). At each postoperative time point, the proportion of $CD3^+$, $CD4^+$, and $CD8^+$ subsets and the serum concentration of IL-2, $TNF-{\alpha}$, and $IFN-{\gamma}$ in group C were all near to those in group B and group D, in which no statistically significant difference was observed. As compared with group A, the proportion of $CD3^+$, $CD4^+$, and $CD8^+$ subsets and the serum concentration of IL-2, $TNF-{\alpha}$, and $IFN-{\gamma}$ were significantly reduced in group C (p<0.05). Conclusion : The artificial nerve established with ADSCs and ACN has no obvious allograft rejection for repairing rat nerve defects.

• Korean Journal of Veterinary Service
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• v.31 no.3
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• pp.331-338
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• 2008

The study was carried out to evaluate the diagnostic efficacy of the tube agglutination test (TAT), enzyme-linked immunosorbent assay (ELISA) and the 2-Mercaptoethanol agglutination test (2-MAT) to detect human brucellosis patients in Korea. We examined 87 serum samples of people in the rural farm areas where bovine brucellosis had been reported. People in this study were divided into seven groups- farmers and their families, veterinarians, veterinary quarantine workers, livestock health control officers, artificial inseminators, livestock traders and healthy control individuals. Among 87 people, 65 were males and 22 were females ranging in age from 13 to 72 years. Of 87 serum samples, ELISA detected 21.84%, TAT detected 11.50% and 2-MAT detected 8.05% Brucella positive sera. Brucella specific IgG ELISA antibody titer was recorder higher in the individuals between the ages of 50 and 65 years. The highest prevalence rate of brucellosis(29.4%) was recorded in the cattle farmers and their family members followed by quarantine veterinary office workers (25%) and practicing veterinarians 01.1%). The majority of the Brucella sero-positive individuals in this study had a history of direct contact with animals.

• Rapid Communication in Photoscience
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• v.2 no.2
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• pp.42-45
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• 2013

Natural photosynthesis utilizes solar energy to convert carbon dioxide and water to energy-rich carbohydrates. Substantial use of sunlight to meet world energy demands requires energy storage in useful fuels via chemical bonds because sunlight is intermittent. Artificial photosynthesis research focuses the fundamental natural process to design solar energy conversion systems. Nicotinamide adenine dinucleotide ($NAD^+$) and $NADP^+$ are ubiquitous as electron transporters in biological systems. Enzymatic, chemical, and electrochemical methods have been reported for NADH regeneration. As photochemical systems, visible light-driven catalytic activity of NADH regeneration was carried out using platinum nanoparticles, molecular rhodium and cobalt complexes in the presence of triethanolamine as a sacrificial electron donor. Pt nanoparticles showed photochemical NADH regeneration activity without additional visible light collector molecules, demonstrating that both photoactivating and catalytic activities exist together in Pt nanoparticles. The NADH regeneration of the Pt nanoparticle system was not interfered with the reduction of $O_2$. Molecular cobalt complexes containing dimethylglyoxime ligands also transfer their hydrides to $NAD^+$ with photoactivation of eosin Y in the presence of TEOA. In this photocatalytic reaction, the $NAD^+$ reduction process competed with a proton reduction.

• Biomedical Science Letters
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• v.9 no.1
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• pp.29-36
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• 2003

Progesterone levels in the blood plasma or skim milk of cows are considered to be very useful indicator fur the detection of estrus cycle and early pregnancy diagnosis. During 13 to 14 days after estrus the level of progesterone in plasma or skim milk were not different between the inseminated arid non-inseminated cows. In the pregnant cows the peak level of progesterone reached on 14th day after artificial insemination (AI), but in the absence of conceptus the level declines after the 14th day slowly, and then very rapidly towards the basal level after the 17th day. This low level persists about 4 days, including those of estrus and ovulation a highly characteristic pattern which differs so markedly from that in the pregnant cows. Progesterone levels in blood plasma or skim milk can provided a reliable diagnosis of early pregnancy and monitoring ovarian activity in cows. The mean $\pm$ standard deviation of milk urea nitrogen(MUN) and protein concentration in the cows at 9 herds were 17.7$\pm$2.35 mg/dL and 3.2$\pm$0.17%, respectively. The days of nonpregnant after parturition was shorter in the cows in which the lower level of MUN than higher level of MUN concentration.

• The Korean Journal of Mycology
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• v.31 no.1
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• pp.14-21
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• 2003

This study was carried out to obtain the basic data on artificial culture of Lampteromyces japonicus. Favorable media for mycerial growth were glucose peptone medium, malt yeast extract, yeast malt peptone, potato dextrose medium. The optimum conditions for the mycelial growth were $30^{\circ}C$ and pH 6.0. Dextrose as a carbon source was favorable to mycelial growth. The optimal dextrose concentration was 1.2%. As nitrogen sources, yeast extract, $(NH_4)_2HPO_4$ and 0.2% for glutamine. The mineral salts of $Al_2(SO_4)_3{\cdot}14H_2O$ were effective and the optimal concentration was 0.1 M.