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941.
942.
Jung-Yeon Han Su-Jin Jung Sang-Woo Kim Yong-Soo Kwon Myong-Jong Yi Jae-Seon Yi Yong-Eui Choi 《Journal of Plant Biology》2006,49(1):26-33
Adventitious roots were produced directly from root segments ofPanax ginseng seedlings when cultured on an MS solid medium containing 3.0 mg L-1 IBA. Omitting NH4NO3 from this medium greatly enhanced both the frequency of adventitious root formation and the number of roots per expiants.
This frequency declined markedly with the age of the root, but could be increased through repeated sub-culturing events. A
two-step procedure that included NH4NO3 free media for the first two weeks of culture, followed by transfer onto media containing NH4NO3 for another four weeks, greatly improved total fresh weights of these adventitious roots compared with a method of continuous
culture over six weeks in media that always contained NH4NO3. Expression of the genes involved in triterpene biosynthesis was analyzed by RT-PCR. Ginsenoside contents were enhanced by
the omission of NH4NO3 and were also greatly increased by treatment with methyl jasmonate. 相似文献
943.
Jeong‐Kyu KIM Chang‐Soo KANG Jong‐Kwon LEE Young‐Ran KIM Hye‐Yun HAN Hwa Kyung YUN 《Entomological Research》2005,35(2):117-120
Repellent efficacies of two natural aroma compounds, citronella and citronellal, against mosquitoes, Culex pipiens pallens, were evaluated both in field and in vitro. In vitro, the experiment was conducted with three controlled bands impregnated with 30% citronella extract, 15% citronella extract and 30% citronellal extract, and with bands impregnated 30% citronella in field. Data was obtained by the means of counting numbers bitten by mosquitoes per unit time, namely human bait method. Percentage repellencies of above three controlled bands were calculated at 86%, 73%, and 78%, respectively in vitro, and 80% in field, showing high repellent effectiveness against mosquitoes. This estimation was also confirmed by t‐test compared between control group and each experimental group. 相似文献
944.
The role of cyclic AMP (cAMP) in ovarian follicular functions in Rana pipiens was investigated with the use of the adenylate cyclase stimulator, forskolin, which is thought to elevate intracellular level of cAMP. Effects of forskolin on oocyte germinal vesicle breakdown (GVBD) and on progesterone production by the follicles were assessed during the course of in vitro culture. Addition of forskolin to culture medium suppressed both progesterone-and frog pituitary homogenate (FPH)-induced meiotic maturation of the oocytes. Inhibitory effects of forskolin were essentially reversible and forskolin completely inhibited GVBD when added during the first four hours of incubation following exposure to progesterone. Forskolin alone stimulated a low level progesterone production by isolated follicles, but markedly stimulated progesterone production when it was supplemented with a low dose of FPH (0.005 pituitary equivalent/ml). Thus, forskolin acts synergistically with FPH on follicle cells to stimulate progesterone production. A higher dose of FPH (0.05 pitui. eq./ml) produced no additional synergistic effect of forskolin. Therefore, forskolin appears to have two contradictory functions in ovarian follicles: it augments FPH induced follicle secretion of meiosis initiator, progesterone, and simultaneously suppresses the maturation of the oocytes triggered by exogenous progesterone or FPH. The data presented indicate that there are two independent adenylate cyclase systems in the ovarian follicles which have separate functions: one in the follicle cells and the other in the oocyte. The two enzyme systems are thus compartmentalized and regulate different biological functions using the same messenger, cAMP. The data provide evidence that in amphibians, as in mammals, pituitary hormones regulate steroid hormone production by follicle cells via a cyclic AMP system. Thus, control of oocyte maturation induction appears to be determined by the relative levels of cAMP present in the follicle cells and oocytes. 相似文献
945.
946.
Kil-yong Lee Ji Won Park Inho Song Ki-young Lee Sangsik Cho Yoon-Hye Kwon Min Jung Kim Seung-Bum Ryoo Seung-Yong Jeong Kyu Joo Park 《World journal of surgical oncology》2018,16(1):232
Background
Perforated colon cancer is a rare complication, but has a high risk of recurrence. However, most studies have not distinguished sealed-off perforation from free perforation, and the prognosis is unclear. The aim of this study was to evaluate the oncologic outcome of colon cancer with sealed-off perforation.Methods
Eighty-six consecutive patients who underwent resection for colon cancer with sealed-off or free perforation were included. We defined sealed-off perforation as a colon perforation with localized abscess identified on operative, computed tomography, or pathologic findings, with no evidence of free perforation, including fecal contamination and dirty fluid collection in the peritoneal cavity. Oncologic outcomes were compared between patients with colon cancer with sealed-off perforation and free perforation using a log-rank test and Cox regression analysis.Results
The sealed-off perforation group included 62 patients, and 24 patients were in the free perforation group. TNM stage and lymphatic, venous, and perineural invasion were similar between the groups. The median follow-up period was 28.9?months (range 0–159). The sealed-off perforation group had better prognosis compared with the free perforation group in terms of progression-free survival (PFS) and overall survival (OS), although there were no statistically significant differences in PFS (5-year PFS 53.7% vs. 40.5%, p?=?0.148; 5-year OS 53.6% vs. 22.9%, p?=?0.001). However, in multivariable analysis using the Cox progression test, sealed-off perforation did not show a significant effect on cancer progression (p =?0.138) and OS (p =?0.727).Conclusions
Colon cancer with sealed-off perforation showed no difference in prognosis compared with free perforation.947.
Potential cow milk xanthine oxidase inhibitory and antioxidant activity of selected phenolic acid derivatives 下载免费PDF全文
Shivraj Hariram Nile Young Soo Keum Arti Shivraj Nile Young Deuk Kwon Doo Hwan Kim 《Journal of biochemical and molecular toxicology》2018,32(1)
Xanthine oxidase (XO) found in all mammals and excess activity leads to urolithiasis. The cow milk XO was purified to 305‐fold with a specific activity of 8.76 EU/mg and overall yield of 87% by using DEAE‐Sepharose chromatography. The phenolics showed potent XO inhibitory effect with Ki, P1 (0.412), P2 (0.632), P3 (0.585), P4 (0.886), P5 (1.633), P6 (0.503), P7 (2.882), P8 (3.761), P9 (4.487), and P10 (5.841) μM. The phenolics P9 and P10 exhibited uncompetitive inhibition; the phenolics P1, P2, P3, P4, and P6 showed competitive inhibition, and other phenolic acids showed noncompetitive inhibition. The studied phenolic compounds showed potent antioxidant activity and expressed as EC50, ranged from, DPPH (4.2–25.8 μg mL–1), ABTS (10.2–42.5 mmol TE 100 g–1), and FRAP (6.3–36.8 mol Fe (II) 100 g–1). The results obtained from this study might be utilized for design of XO inhibitors and as antigout agent. 相似文献
948.
Signalling requirements for Erwinia amylovora‐induced disease resistance,callose deposition and cell growth in the non‐host Arabidopsis thaliana 下载免费PDF全文
Safae Hamdoun Min Gao Manroop Gill Ashley Kwon John L. Norelli Hua Lu 《Molecular Plant Pathology》2018,19(5):1090-1103
Erwinia amylovora is the causal agent of the fire blight disease in some plants of the Rosaceae family. The non‐host plant Arabidopsis serves as a powerful system for the dissection of mechanisms of resistance to E. amylovora. Although not yet known to mount gene‐for‐gene resistance to E. amylovora, we found that Arabidopsis activated strong defence signalling mediated by salicylic acid (SA), with kinetics and amplitude similar to that induced by the recognition of the bacterial effector avrRpm1 by the resistance protein RPM1. Genetic analysis further revealed that SA signalling, but not signalling mediated by ethylene (ET) and jasmonic acid (JA), is required for E. amylovora resistance. Erwinia amylovora induces massive callose deposition on infected leaves, which is independent of SA, ET and JA signalling and is necessary for E. amylovora resistance in Arabidopsis. We also observed tumour‐like growths on E. amylovora‐infected Arabidopsis leaves, which contain enlarged mesophyll cells with increased DNA content and are probably a result of endoreplication. The formation of such growths is largely independent of SA signalling and some E. amylovora effectors. Together, our data reveal signalling requirements for E. amylovora‐induced disease resistance, callose deposition and cell fate change in the non‐host plant Arabidopsis. Knowledge from this study could facilitate a better understanding of the mechanisms of host defence against E. amylovora and eventually improve host resistance to the pathogen. 相似文献
949.
Deok Ho Kwon In-Hong Jeong Sung Jun Hong Myung-Pyo Jung Ki-Su Kim Si Woo Lee Si Hyeock Lee 《Journal of Asia》2018,21(1):293-300
The small brown planthopper (SBPH, Laodelphax striatellus Fallén) is an important pest that causes severe yield losses in rice by transmitting viral plant diseases. For the proper management of this pest, therefore, it is necessary to understand its temporal and spatial dynamics by establishing a periodical monitoring system. A dataset, including the number of SBPHs by location, collection method [aerial collection net (AeCN) or light trap (LT)] and period (May–Aug.) for five years (2011–2015) was provided by the Rural Developmental Administration, and missing values were imputed using multiple imputation methods. Of the 15,848 individuals collected, approximately 47% and 52.9% were collected using the AeCN and LT methods, respectively. Large numbers of SBPHs were generally collected from western coastal regions using AeCNs but not LTs. A high incidence of migratory SBPHs was observed during Julian days 144–166 using the AeCN method, with slightly different migration periods in each year. Generally, the migratory SBPHs made up 39.4% of the total populations of SBPHs during those periods. According to clustering analysis, the migratory region was located along the western coastal regions. Putative migration paths were estimated by trajectory cluster analyses using meteorological data. Interestingly, an L-shaped trajectory path emerged as a potentially important route for migratory SBPHs, passing through major wheat cultivation areas in Henan, Anhui, Jiangsu, and Zhejiang provinces in China, where high densities of SBPHs occur from late May to early June. These results would provide valuable information to predict the incidence period of migratory SBPHs and establish a proactive management system against SBPH, including the basis for the detection of hazardous factors and decisions regarding appropriate pesticide treatment periods. 相似文献
950.
The small brown planthopper, Laodelphax striatellus Fallén, is a major migratory pest from China to Korea and transmits viral diseases of rice plants. In this study, we compared the genetic structures of overwintered indigenous Korean and Chinese populations. The eight Korean populations consisted of 33 haplotypes, and 16 of these were newly identified. The genetic diversity of the Korean population revealed high haplotype diversity (Hd) and low nucleotide diversity (π) of 0.86 ± 0.017 and 0.0024 ± 0.0001 on average, respectively. These values for the Chinese population were Hd = 0.92 ± 0.016 and π = 0.0026 ± 0.0002. Overall, genetic distances by pairwise FST were generally low, ranging from ? 0.022 to 0.089. Moreover, the Korean population revealed its ongoing population expansion by showing negative values in the neutrality test (Tajima's D = ? 1.4, Fu's Fs = ? 15.8) and a unimodal pattern in the mismatch distribution analysis. The genetic structures and population relationships were determined using 8 indigenous Korean and 30 Chinese populations by Bayesian approaches and population tree construction, respectively. The genetic structure was inferred as five (K = 5), and all indigenous Korean populations as well as 10 Chinese populations from the Shanghai city, Anhui, Henan, Jiangsu, Liaoning, Shandong, and Zhejiang provinces were grouped into ‘G3’. These results provide partial support for unidirectional gene flow by migratory Chinese populations into Korea. Further analysis conducted using specimens from China and Korea collected in similar periods is necessary to clarify the migration population's origin and its effect on the genetic structure of the indigenous populations. 相似文献