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排序方式: 共有461条查询结果,搜索用时 312 毫秒
411.
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Sangkeun Son Sung-Kyun Ko Mina Jang Jong Won Kim Gil Soo Kim Jae Kyoung Lee Eun Soo Jeon Yushi Futamura In-Ja Ryoo Jung-Sook Lee Hyuncheol Oh Young-Soo Hong Bo Yeon Kim Shunji Takahashi Hiroyuki Osada Jae-Hyuk Jang Jong Seog Ahn 《Marine drugs》2016,14(4)
Salterns, one of the most extreme natural hypersaline environments, are a rich source of halophilic and halotolerant microorganisms, but they remain largely underexplored ecological niches in the discovery of bioactive secondary metabolites. In continued efforts to investigate the metabolic potential of microbial populations from chemically underexplored sites, three new lipopeptides named iturin F1, iturin F2 and iturin A9 (1–3), along with iturin A8 (4), were isolated from Bacillus sp. KCB14S006 derived from a saltern. The structures of the isolated compounds were established by 1D-, 2D-NMR and HR-ESIMS, and their absolute configurations were determined by applying advanced Marfey’s method and CD spectroscopy. All isolates exhibited significant antifungal activities against various pathogenic fungi and moderate cytotoxic activities toward HeLa and srcts-NRK cell lines. Moreover, in an in vitro enzymatic assay, compound 4 showed a significant inhibitory activity against indoleamine 2,3-dioxygenase. 相似文献
414.
Substitution effect of sea tangle (ST) (Laminaria japonica) with tunic of sea squirt (SS) (Halocynthia roretzi) in diet on growth and carcass composition of juvenile abalone (Haliotis discus,Reeve 1846) 下载免费PDF全文
B. Jang P.Y. Kim H.S. Kim K.W. Lee H.J. Kim D.G. Choi S.H. Cho B. Min K. Kim H. Han 《Aquaculture Nutrition》2018,24(1):586-593
Substitution effect of sea tangle (ST) with tunic of sea squirt (SS) in diet on growth and carcass composition of juvenile abalone was determined. One thousand four hundred and seventy abalones were distributed into 21 containers. Six formulated diets in triplicate were prepared. A 200 g/kg ST was included into the ST0 diet. The 200, 400, 600, 800 and 1000 g/kg of ST were substituted with the same amount of tunic of SS, referred to as the ST200, ST400, ST600, ST800 and ST1000 diets, respectively. Finally, Undaria was prepared to compare effect of the formulated diets on performance of abalone. The experimental diets were fed to abalone for 16 weeks. Weight gain of abalone fed the ST400 diet was higher than that of abalone fed the ST0, ST600, ST800 and ST1000 diets and Undaria. Weight gain of abalone fed the formulated diets was higher than that of abalone fed the Undaria. The chemical composition of the carcass of abalone was affected by dietary substitution of ST with tunic of SS. In conclusion, ST could be completely substituted with tunic of SS without retardation in performance of abalone. Abalone fed the ST400 diet substituting 400 g/kg ST with tunic of SS achieved the best growth. 相似文献
415.
Background:Whey permeate is an effective lactose source for nursery pigs and the most benefits are obtained when pigs are at 7 to 11 kg BW.Altering weaning ages could cause different length of early-weaner phases until 7 kg BW and thus it would influence the dietary need of whey permeate during 7 to 11 kg BW of pigs.This study aimed to evaluate if weaning ages would affect the dietary needs of whey permeate for optimum growth performance of pigs at 7 to 11 kg BW.Methods:A total of 1,632 pigs were weaned at d 21(d 21.2±1.3)or d 25(d 24.6±1.1)after birth.All pigs had a common early-weaner feeds until they reached 7 kg BW.When pigs reached 7 kg BW within a weaning age group,they were allotted in a randomized complete block design(2×4 factorial).Two factors were weaning age groups(21 and 25 d of age)and varying whey permeate levels(7.50%,11.25%,15.00%,and 18.75%).Data were analyzed using the GLM and NLIN procedures of SAS for slope-ratio and broken-line analyses to determine the growth response to whey permeate and optimal daily whey permeate intake for the growth of the pigs weaned at different ages.Results:Pigs weaned at 21 d of age had a common diet for 11 d to reach 7 kg BW whereas pigs weaned at 25 d of age needed 2 d.The G:F of pigs weaned at 25 d of age responded to increased daily whey permeate intake greater(P<0.05)than pigs weaned at 21 d of age.Breakpoints were obtained(P<0.05)at 88 and 60 g/d daily whey permeate intake or 17.0%and 14.4%of whey permeate for G:F of pigs weaned at 21 and 25 d of age,respectively.Conclusion:Pigs weaned at an older age with a short early-weaner phase had a greater growth response to whey permeate intake compared with pigs weaned at a younger age with a long early-weaner phase.Altering weaning ages affected dietary needs of whey permeate for optimum growth performance of pigs from 7 to 11 kg BW. 相似文献
416.
Won-Ho Nam Jin-Yong Choi Seung-Hwan Yoo Min-Won Jang 《Paddy and Water Environment》2012,10(3):197-207
Since predicted changes in climate will modify temperature and rainfall patterns, there are concerns about the potential impacts of these changes on agricultural drought and agricultural water resources management. An agricultural drought is influenced by several factors such as rainfall, soil characteristics, crops, and reservoir water supply and may be defined as the imbalance of water circulation in paddy and water environments. In particular, soil moisture and water supply for reservoir demand are the most direct and important indicators of agricultural drought events. In the past, conventional drought management approaches based on climatic and meteorological observations have been the primary tools used for measuring drought severity. Because of the spatial and temporal variability and multiple impacts of drought, it is necessary to improve tools to determine the onset, severity, spatial extent, and end of the drought conditions. Improved and available data for mapping and monitoring of this phenomenon are also needed. Effective and efficient drought management can be achieved through drought monitoring based on the ability to assess current conditions and provide improved tools to adapt and mitigate the impacts of future changes. In this article, a methodology is developed to support the risk-based decision-making process involved in agricultural drought management using the following four strategies: drought assessment and monitoring, drought forecast and outlook, drought countermeasures, and drought records management. 相似文献
417.
418.
Estimation of the design water requirement (DWR) is a key part of design and operation of agricultural water resource systems. DWR is determined from frequency analysis of crop water requirement, and the reference return period has been 10 years in South Korea. This study aimed to propose a guideline for determining DWR using Food and Agriculture Organization (FAO) Penman–Monteith method and optimal probability distribution function (PDF). To find an optimal PDF, nine types of PDF were tested using the Kolmogorov–Smirnov (K–S) and Probability Plot Correlation Coefficient (PPCC) goodness-of-fit methods. From the test, the Generalized Logistic (GLO) was selected and DWRs were estimated using the chosen optimal PDF. To demonstrate the DWR differences among the PDFs, DWR and drought reference design year were compared for the three selected PDFs, GLO, Generalized Extreme Values (GEV) and Weibull (WBU). The results would effect on the design and operation of the agricultural water resources structures in terms of capacity and capability in South Korea. 相似文献
419.
Continuous photografting onto polypropylene fabrics in the absence of inert gases was carried out to improve hydrophilic property
of PP fabrics, which was padded with a formulated solution of 2-hydroxyethyl methacrylate(HEMA) and benzophenone as a monomer
and a photoinitiator, respectively. The grafting yield increased with increases in benzophenone concentration up to 30 % on
the weight of the monomer and UV energy up to of 38 J/cm2, while 30 % HEMA concentration was optimal for the grafting efficiency. The physicochemical properties of the grafted PP
fabrics were monitored by FT-IR, SEM, zeta potential, and dyeability to a cationic dye. The grafting increased O1s/C1s content and remarkably produced more negative zeta potentials compared with the pristine PP fabric. Also the grafted PP showed
the increased dyeability to cationic dyes with increasing graft yield resulting from the enhanced electrostatic interaction
between the dyes and negatively charged surface of the grafted PP fiber. In addition, improved hydrophilic property of grafted
PP fabrics was ascertained by more rapid water wetting time and higher water absorbency. 相似文献
420.
Hydrophobic poly(lactic acid), PLA, was modified to give hydrophilicity and dyeability to cationic dyes via UV/O3 irradiation. The UV irradiation treatment caused ester linkage of PLA surface to break down resulting in reduced molecular
weight and generation of new photooxidized products as indicated in subtracted ATR spectra and ESCA analysis. It was found
that water contact angle decreased from 61 ° to 39 ° and surface energy slightly increased with increasing UV energy, which
was attributed to significant contribution of polar component rather than nonpolar component resulting from the surface photooxidation
of PLA. Also the surface treatment increased dyeability of PLA to C.I. Basic Blue 41 in terms of both K/S and %E. The increased dyeability may be due to photochemically introduced anionic and dipolar dyeing sites which electrostatically
interact with the cationic dye as ascertained by the decreased zeta potential and its pH dependence of the modified PLA. 相似文献