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排序方式: 共有251条查询结果,搜索用时 15 毫秒
161.
Jae Yeon HWANG Kwang-Hwan CHOI Dong-Kyung LEE Seung-Hun KIM Eun Bae KIM Sang-Hwan HYUN Chang-Kyu LEE 《The Journal of reproduction and development》2015,61(6):533-540
X-chromosome inactivation (XCI) is an epigenetic process that equalizes expression of X-borne genes between
male and female eutherians. This process is observed in early eutherian embryo development in a
species-specific manner. Until recently, various pluripotent factors have been suggested to regulate the
process of XCI by repressing XIST expression, which is the master inducer for XCI. Recent
insights into the process and its regulation have been restricted in mouse species despite the evolutionary
diversity of the process and molecular mechanism among the species. OCT4A is one of the
represented pluripotent factors, the gate-keeper for maintaining pluripotency, and an XIST
repressor. Therefore, in here, we examined the relation between OCT4A and X-linked genes in
porcine preimplantation embryos. Three X-linked genes, XIST,
LOC102165544, and RLIM, were selected in present study because their
orthologues have been known to regulate XCI in mice. Expression levels of OCT4A were
positively correlated with XIST and LOC102165544 in female blastocysts.
Furthermore, overexpression of exogenous human OCT4A in cleaved parthenotes generated
blastocysts with increased XIST expression levels. However, increased XIST
expression was not observed when exogenous OCT4A was obtained from early blastocysts. These
results suggest the possibility that OCT4A would be directly or indirectly involved in
XIST expression in earlier stage porcine embryos rather than blastocysts. 相似文献
162.
Jung-Hyun Kim Dana Hyunjung Ahn Je-Sung Moon Hyun-Jung Han Kieun Bae Kyong-Ah Yoon 《The Veterinary quarterly》2021,41(1):153
Transitional cell carcinoma (TCC) is the most common malignant tumor of the canine urinary tract. In this case study, a dog with metastatic urethral TCC was treated with sorafenib. The tumor expression levels of receptor tyrosine kinase genes, including VEGFR-1, VEGFR-2, PDGFR-α, PDGFR-β, ALK, EGFR, ErbB2, and B-RAF, were analyzed. VEGFR was overexpressed in tumor tissues compared to the normal tissues. Considering the high frequency of B-RAF mutation in canine urological tumors, the B-RAF gene was examined, and the B-RAF V595E mutation was detected in the tumor tissue. Therefore, the antitumor effect of sorafenib, a multi-tyrosine kinase inhibitor, on unresectable metastatic urethral TCC characterized by B-RAF V595E was evaluated and circulating cell-free tumor DNA (ctDNA) was assessed for monitoring the treatment response. After the initiation of oral sorafenib therapy (4 mg/kg/day escalated to 10 mg/kg/day), the dysuria was alleviated gradually, and the patient remained stable for 3 months. During that treatment period, the patient showed various levels of changes associated with B-RAF V595E mutation in ctDNA as evident from longitudinal plasma samples after initiation of sorafenib therapy. The findings of this study suggest that ctDNA may serve as a useful non-invasive tool for monitoring the treatment response to anticancer drugs. 相似文献
163.
Bae HK Lee SB Park CS Shim JH Lee HY Kim MJ Baek JS Roh HJ Choi JH Choe EO Ahn DU Park KH 《Journal of agricultural and food chemistry》2002,50(11):3309-3316
Ascorbic acid (1), a natural antioxidant, was modified by employing transglycosylation activity of Bacillus stearothermophilus maltogenic amylase with maltotriose and acarbose as donor molecules to enhance its oxidative stability. The transglycosylation reaction with maltotriose as donor created mono- and di-glycosyl transfer products with an alpha-(1,6)-glycosidic linkage. In addition, two acarviosine-glucosyl transfer products were generated when transglycosylation was performed with acarbose as a donor. All transfer products were observed by TLC and HPLC, and purified by Q-sepharose anion exchange and Biogel P-2 gel permeation chromatographies. LC/MS and (13)C NMR analyses revealed that the structures of the transfer products were 6-O-alpha-D-glucosyl- (2) and 6-O-alpha-D-maltosyl-ascorbic acids (3) in the reaction of maltotriose, and 6-O-alpha-acarviosine-D-glucosyl- (4) and 2-O-alpha-acarviosine-D-glucosyl ascorbic acids (5) in the reaction of acarbose. The stability of the transglycosylated ascorbic acid derivatives was greatly enhanced against oxidation by Cu(2+) ion and ascorbate oxidase. Among them, compound 3 proved to be the most stable against in vitro oxidation. The antioxidant effects of glycosyl-derivatives of ascorbic acid on the lipid oxidation in cooked chicken breast meat patties indicated that they had antioxidant activities similar to that of ascorbic acid. It is suggested that the transglycosylated ascorbic acids can possibly be applied as effective antioxidants with improved stability in food, cosmetic, and other applications. 相似文献
164.
Kim DH Kim JH Bae SE Seo JH Oh TK Lee CH 《Journal of agricultural and food chemistry》2005,53(7):2541-2545
Pigment extracts from the root of Lithospermum erythrorhizon are used as natural red dyes, as well as basic drugs due to their numerous pharmacological activities. In recent years, the demand for such natural pigment materials has increased; however, in natural dye production, the pigment yield is strongly affected by the source of cultivation, extracting conditions, and solvents. Accordingly, this study proposes a method of enzymatic pigment production based on the introduction of hydrolytic enzymes prior to the usual extraction to avoid repeated pigment extraction. The matrix destruction in the epidermal layer of the root by the enzymes was found to improve the pigment extractability, that is, the increment of K(L), the mass transfer coefficient, representing the pigment mobility in the epidermal layer. The root tissue maceration by the hydrolytic enzymes was also measured to evaluate the pigment extractability, and a linear relationship was observed between the K(L) values and the tissue maceration up to the addition of 3000 units/g of xylanase, indicating that the enzymatic maceration proportionally increases the interfacial area between the pigment and the solvent. Bacillus sp. DX107 xylanase only served to increase the extractability of the pigment by loosening the root shell matrix, without affecting the contents and color properties of the pigment, as almost no difference was found in the color between the pigments extracted using xylanase and those extracted according to the traditional method. 相似文献
165.
Non-genotoxic diamines 2,2′-dimethyl-5,5′-dipropoxybenzidine and 5,5′-dipropoxy-benzidine were employed as potential alternatives to benzidine in the synthesis and evaluation of new direct dyes for cotton. Assessment of the resultant dyes indicated that both diamines can be used to prepare new direct dyes having colors and fastness properties that make them comparable to commercial direct dyes, and that the structures of the new direct dyes can be confirmed by negative ion electrospray mass spectrometry (ESMS). The mutagenic properties of new direct dyes were established using the standard Ames Salmonella mammalian mutagenicity assay. 相似文献
166.
The viscosity effect of matrix polymer on melt exfoliation behavior of an organoclay in poly(ε-caprolactone) (PCL) was investigated. The viscosity of matrix polymer was controlled by changing the molecular weight of
poly(ε-caprolactone), the processing temperature, and the rotor speed of a mini-molder. Applied shear stress facilitates the diffusion
of polymer chains into the gallery of silicate layers by breaking silicate agglomerates down into smaller primary particles.
When the viscosity of PCL is lower, silicate agglomerates are not perfectly broken into smaller primary particles. At higher
viscosity, all of silicate agglomerates are broken down into primary particles, and finally into smaller nano-scale building
blocks. It was also found that the degree of exfoliation of silicate layers is dependent upon not only the viscosity of matrix
but thermodynamic variables. 相似文献
167.
168.
Young-Baek Hur Jean-Hee Bae Sung-Bum Hur 《Journal of the World Aquaculture Society》2005,36(2):179-187
The development and larval morphology of four venerid calms, Ruditapes philippinarum, Mactra veneriformis, Cyclina sinensis , and Meretrix lusoria , which cohabit the intertidal zone in western coastal Korea, were compared using laboratory culture techniques. At 87 μm, the fertilized eggs of C. sinensis and M. lusoria were the largest and at 53 μm, those of M. veneriformis were the smallest. D-shaped larvae of M. lusoriu were the largest and those of M. veneriformis were the smallest measuring at 135 μm and 89 μm, respectively. D-shaped larvae of R. philippinarum and M. lusoria had symmetrical shoulder angles and an elliptical ventral form, in contrast to the asymmetrical shoulder angles and round ventral forms of M. veneriformis and C. sinensis . In general, pediveliger larvae of all species in the study were yellow, but those of M. veneriforks and C sinenis were a more pronounced yellow. In between the early D-shaped and pediveliger stage, 7 and 17 d elapsed for M. lusonia and C. sinensis larvae, respectively. In the early larval stages for all species, the sheU length was longer than the height. However, shell length and height later became approximately the same size in all species except R. philippinarum , which exhibited a flat shape. These results indicate that for these four venerid clams, the different characteristics in larval growth and external morphology provide the evidence necessary for larval identification of natural seed production despite the fact that they spawn concurrently in the intertidal zone. 相似文献
169.
A highly selective colorimetric chemosensor for Hg2+ based on the semisquaraine (BSQ) containing benzothiazole moiety was investigated. BSQ showed color change only with Hg2+, but it showed no significant changes upon addition of other metal ions such as Ca2+, Pb2+, Al3+, Ce2+, Ba2+, Ni2+, Cd2+, Zn2+, and Mg2+. Hg2+ ions coordinated to the BSQ forming 1:1 complex. The experimental data and conclusions are rationalized by DMol3 calculation results. 相似文献
170.
Synthesis and application of alkyl-substituted disazo yellow dyes for unmodified polypropylene fiber
Taekyeong Kim Jongsuc Jung Songi Son Seokhan Yoon Mikyung Kim Jin-Seok Bae 《Fibers and Polymers》2008,9(5):538-543
The several disazo dyes having different alkyl substituents were synthesized to dye unmodified polypropylene fiber. The affinity
of the dyes onto unmodified polypropylene was increased with the increase of the length of alkyl substituents. Therefore,
the heptyl-substituted dye having the longest alkyl group in this experiment showed very high color strength of dyeings with
K/S value of over 24 at maximum absorption wavelength. The color fastnesses to washing, rubbing and light were also improved
significantly for the longer alkyl substituted dyes, so that the heptyl-substituted dye exhibited a rating of 4∼5 for all
kinds of fastnesses. 相似文献