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581.
Yun Sun Lee Hye Mi Park Nam-Hoon Kim Nomar E. Waminal Yeon Jeong Kim Ki-Byung Lim Jin Hong Baek Hyun Hee Kim Tae-Jin Yang 《Genetic Resources and Crop Evolution》2016,63(2):235-242
Aloe species, which have been used as medicinal plants, belong to the Asphodelaceae family consisting of 530 species. In this study, genetic diversity and phylogenetic relationships among 40 Aloe species including a putative interspecies hybrid were analyzed using PCR band profiles from eight chloroplast intergenic space markers and nucleotide sequence diversity in the psbK–psbI intergenic region. A phylogenetic tree based on psbK–psbI sequences supported the revised classification of the genus Aloe as polyphyletic with several species be re-allocated into three genera Kumara, Aloidendron, and Aloiampelos. Further, the origin of the putative interspecies Aloe hybrid was characterized through molecular cytogenetics. Fluorescence and genomic insitu hybridization illustrated that the hybrid has a bimodal karyotype with a chromosome complement of 2n = 14, of which complementary halves were derived from two parental species, A. vera and A. arborescens. These findings revealed that the hybrid species was allodiploid. The phylogenetic analysis showed that A. arborescens was the maternal genome donor of the hybrid, as both have identical chloroplast genome sequences. We thus conclude that the allodiploid hybrid should be called A. arborescens × A.vera. 相似文献
582.
Schepetkin IA Khlebnikov AI Ah SY Woo SB Jeong CS Klubachuk ON Kwon BS 《Journal of agricultural and food chemistry》2003,51(18):5245-5254
Mumie, a semihard black resin formed by long-term humification, is believed to have therapeutic properties. Although mumie has been used in folk medicine since ancient times, there is little information available concerning the physicochemical properties of its constituents and the mechanisms of its therapeutic efficacy. For this study crude mumie was fractionated into fulvic acid (FA), humic acid (HA), humin, hymatomelanic acid, and two low molecular weight fractions (LMW1 and LMW2). The FA fraction was divided into five subfractions, FA1-FA5. The mumie fractions were characterized by IR, UV-vis, and fluorescence spectroscopy. Total carbohydrate content in the fractions was analyzed using the phenol reaction method. The relative content of polar groups and nonpolar hydrocarbon fragments in the mumie fractions correlated well with solubility in an aqueous medium. Biological characterization was performed using only the FA fractions. FA1 and FA2 enhanced the production of reactive oxygen species (ROS) and nitric oxide in murine peritoneal macrophages, as determined with the use of 2',7'-dichlorofluorescin diacetate and Griess reagent, respectively. The enchancement of ROS and nitric oxide production correlated with the level of total carbohydrates in the fractions. Murine splenic lymphocytes treated with FA1 showed a dose-dependent increase in [(3)H]thymidine uptake. These findings suggest that FA derived from mumie has immunomodulatory activity. 相似文献
583.
Alisha Wehdnesday Bernardo Reyes Tran Xuan Ngoc Huy Son Hai Vu Hyun Jin Kim Jin Ju Lee Jeong Soo Choi John Hwa Lee Suk Kim 《Journal of veterinary science (Suw?n-si, Korea)》2021,22(2)
BackgroundWe previously elucidated the protective mechanism of Korean red ginseng oil (RGO) against Brucella abortus infection, and our phytochemical analysis revealed that palmitic acid (PA) was an abundant component of RGO. Consequently, we investigated the contribution of PA against B. abortus.ObjectivesWe aimed to investigate the efficacy of PA against B. abortus infection using a murine cell line and a murine model.MethodsCell viability, bactericidal, internalization, and intracellular replication, western blot, nitric oxide (NO), and superoxide (O2-) analyses and flow cytometry were performed to determine the effects of PA on the progression of B. abortus infection in macrophages. Flow cytometry for cytokine analysis of serum samples and bacterial counts from the spleens were performed to determine the effect of PA in a mouse model.ResultsPA did not affect the growth of B. abortus. PA treatment in macrophages did not change B. abortus uptake but it did attenuate the intracellular survivability of B. abortus. Incubation of cells with PA resulted in a modest increase in sirtuin 1 (SIRT1) expression. Compared to control cells, reduced nitrite accumulation, augmented O2-, and enhanced pro-inflammatory cytokine production were observed in PA-treated B. abortus-infected cells. Mice orally treated with PA displayed a decreased serum interleukin-10 level and enhanced bacterial resistance.ConclusionsOur results suggest that PA participates in the control of B. abortus within murine macrophages, and the in vivo study results confirm its efficacy against the infection. However, further investigations are encouraged to completely characterize the mechanisms involved in the inhibition of B. abortus infection by fatty acids. 相似文献
584.
Inorganic compound leakage and change of carbohydrate were measured in Ulmus parvifolia seeds throughout accelerated aging under 35°C and 75% relative humidity (RH) to investigate whether these indicators can
be used as a rapid vigor test for efficient seed bank management. Accelerated aging seeds treated for 0–14 days exhibited
loss of germinability in the longest aging treated seeds (11%, 14 days) compared to a good performance of 52% for control
(0 day) seeds. Leachate electrical conductivity (EC) increase had strong negative correlation with seed vigor (−0.9). Magnesium
ion concentration in electrolyte leakage from artificial aged seeds showed positive correlation (r = 0.94, P < 0.01). The ratios of inorganic ions showed that K+/Mg2+, Ca2+/Mg2+, and Na+/Mg2+ were inversely correlated with germination (−0.93, −0.82, and −0.91, respectively). Increases in starch and total soluble
sugar content in aged seeds were associated with a decrease in seed vigor. In conclusion, EC, magnesium ion concentration,
K+/Mg2+, Ca2+/Mg2+, and Na+/Mg2+ ratios and starch and total soluble sugar content could provide a sensitive and accurate index for the assessment of U. parvifolia seed vigor. 相似文献
585.
Park JY Ogletree DF Salmeron M Ribeiro RA Canfield PC Jenks CJ Thiel PA 《Science (New York, N.Y.)》2005,309(5739):1354-1356
Strong friction anisotropy is found when the twofold surface of an atomically clean aluminum-nickel-cobalt quasicrystal slides against a thiol-passivated titanium-nitride tip. Friction along the aperiodic direction is one-eighth as much as that along the periodic direction. This anisotropy, which is about three times as large as the highest value observed in anisotropic crystalline surfaces, disappears after the surface is oxidized in air. These results reveal a strong connection between interface atomic structure and the mechanisms by which energy is dissipated, which likely include electronic or phononic contributions, or both. 相似文献
586.
A methodology for the objective evaluation of water repellency is studied using image analysis of the sprayed pattern on woven
fabrics according to a standard spray test (AATCC Test Method 22-2001). The wet area ratio obtained from the spray standard
test ranking is found to be exponentially related with its water repellency rating. Mean filtering is used to remove the effect
of weave texture and the transmitted light through interyarn spaces. The ring frame of the instrument and wet region are recognized
using Otsu thresholding technique. And Hough transform and outline operation are used to obtain the size and position of the
ring frame. The objective assessment of the water repellency using image processing can reduce unnecessary confusion in the
subjective determination of the water repellency. 相似文献
587.
In order to prepare high molecular weight poly(methyl methacrylate) (PMMA)/silver nanocomposite microspheres, methyl methacrylate
was suspension-polymerized in the presence of silver nanoparticles at low temperature with 2,2′-azobis(2,4-dimethylvaleronitrile)
as an initiator. The rate of conversion was increased by increasing the initiator concentration. When silver nanoparticles
were added, the rate of polymerization decreased slightly. High monomer conversion (about 85 %) was obtained in spite of low
polymerization temperature of 30°C. Under controlled conditions, PMMA/silver microspheres with various number-average degrees
of polymerization (6,000–37,000) were prepared. Morphology studies revealed that except for normal suspension microspheres
with a smooth surface, a golf ball-like appearance of the microspheres was observed, due to the migration and aggregation
of the hydrophilic silver nanoparticles at the sublayer beneath the microsphere’s surface. 相似文献
588.
589.
Sung Eun Kim Yong Woo Cho Eun Jung Kang Ick Chan Kwon Eunhee Bae Lee Jung Hyun Kim Hesson Chung Seo Young Jeong 《Fibers and Polymers》2001,2(2):64-70
A three-dimensional, porous collagen/chitosan complex sponge was prepared to closely simulate basic extracellular matrix (ECM)
constitutes, collagen and glycosaminoglycan. The complex sponge was prepared by a lyophilization method and had the regular
network with highly porous structure, suitable for cell adhesion and growth. The pores were well interconnected, and their
distribution was fairly homogeneous. The complex sponge was crosslinked using 1-ethyl-3-(3-dimethyl aminopropyl) carbodiimide
(EDC) and N-hydroxysuccinimide (NHS) to increase its biological stability and enhance its mechanical properties. The crosslinking
medium had a great effect on the inner structure of the sponge. The homogeneous, porous structure of the sponge was remarkably
collapsed in an aqueous crosslinking medium. However, the morphology of the sponge remained almost intact in a water/ethanol
mixture crosslinking milieu. Mechanical properties of the collagen/chitosan sponge were significantly enhanced by EDC-mediated
crosslinking. The potential of the sponge as a scaffold for tissue engineering was investigated using a Chinese hamster ovary
cell (CHO-K1) line. 相似文献
590.
Tae?Won?SonEmail author Kwang?Il?Kim Nam?Hun?Kim Min?Gi?Jeong Young?Hun?Kim 《Fibers and Polymers》2003,4(1):20-26
The thermal behavior, morphology, ester-interchange reaction of Poly(trimethylene terephthalate) (PTT)/Poly(ethylene terephthalate)
(PET) melt blends were investigated over the whole composition range(xPTT/(1-x)PET) using a twinscrew Brabender. The melt
blends were analyzed by differential scanning calorimetry (DSC), nuclear magnetic resonance spectroscopy (13C-NMR), and scanning electron microscopy (SEM). Single glass transition temperature (T
g
) and cold crystallization temperature (T
cc
) were observed in all melt blends. Melt blends were found to be due to the ester-interchange reaction in PTT/PET blend. Also
the randomness of copolymer increases because transesterification between PTT and PET increases with increasing blending time.
This reaction increases homogeneity of the blends and decreases the degree of crystallinity of the melt blends. In PTT-rich
blends, mechanical properties decrease with increase of PET content compared with that of pure PTT. And, in PET-rich blends,
tensile modulus decreases with increase of PTT content, but tensile strength and elongation is similar to that of pure PET. 相似文献