排序方式： 共有82条查询结果，搜索用时 15 毫秒
41.
企业资信的模糊数学评价方法 总被引：1，自引：0，他引：1
根据企业资信定量指标的特性及定性指标的模糊性 ,提出了企业资信优序评价的新模型 ,该模型有效地解决了传统资信评价中软指标的处理难点 ,提高了企业资信评价的准确度 ,具有一定的实用性 . 相似文献
42.
Sulfated Galactans of Champia indica and Champia parvula (Rhodymeniales,Rhodophyta) of Indian Waters
Sanjay Kumar Devaki Nandan Ramavatar Meena Kamalesh Prasad Arup K. Siddhanta 《Journal of carbohydrate chemistry》2013,32(1):47-60
Sulfated galactans of the red seaweed species Champia indica and Champia parvula of Indian waters were extracted and purified by ion exchange chromatography. These were characterized by infrared and 13C NMR spectroscopy as well as by GC-MS analysis of alditol acetate derivatives produced by reductive hydrolysis/acetylation of sulfated and desulfated and their methylated samples. The sulfated galactans of these Champia species contained alternating β-(1→3)-linked galactopyranosyl units with sulfation at the 2-position and α-(1→4)-linked galactopyranosyl units having sulfation at both the 2- and 3-positions. Other minor substitutions included 6-O-methyl ether of the β-(1→3)-linked galactose residues only in Champia parvula. 相似文献
43.
The antibacterial activity of an ethylacetate neem cake extract (NCE) against bacteria that affect meat quality, namely Campylobacter jejuni, Carnobacterium spp., Lactobacillus curvatus, Lactobacillus sakei and Leuconostoc sp., is reported. The antibacterial activity was detected using standardised disc diffusion and macrodilution methods. The bacterial growth inhibition zone ranged from 11.33 ± 0.58 to 22.67 ± 0.58 mm (100 μL NCE). There is significant difference between the growth inhibition zone of NCE and the control (ciprofloxacin 100 μg). The percent of bacterial growth reduction range was 79.75 ± 1.53 to 90.73 ± 1.53 (100 μg NCE) as compared with control (without NCE). NCE in different amounts counteracted the growth of all tested bacteria. 相似文献
44.
《International Journal of Polymer Analysis and Characterization》2012,17(1):72-84
The present work deals with the graft copolymerization of acrylic acid onto natural Cannabis indica fiber by using Ce3+-HNO3 redox initator system under the influence of microwave radiation (MWR). The reaction conditions such as time, initator concentration, monomer concentration, nitric acid concentration, and pH were optimized to get the maximum percentage of grafting (9.86%). The graft copolymers thus formed were characterized by FT-IR, X-ray diffraction, thermogravimetric analysis, and scanning electron microscope techniques. Raw Cannabis indica fiber and graft copolymerized fibers were also subjected to evaluation of some of their properties like swelling behavior, moisture absorbance, and resistance towards chemicals. 相似文献
45.
《Natural product research》2012,26(2):95-98
Abstract The natural insecticide azadirachtin (1) has been isolated from dried cells of the Neem tree (A. indica) grown in tissue culture on a synthetic medium and shown chemically to be identical with the compound isolated from the seeds of the Neem tree, by 1H NMR and mass spectra. 相似文献
46.
《Natural product research》2012,26(3):179-182
Abstract Fresh undried winter leaves of Azadirachta indica were fed with [2-14C, 4R-3H1] MVA. Atomic and isotopic ratios in nimocinol & nimocinolide, thus isolated showed the loss of one 14C from the side chain and four tritium atoms - one from side chain and three from apotetracyclic triterpene skeleton. The biosynthetic pathway thus established suggested the involvement of euphol (Δ8,9 compound) which is isomerised to butyrospermol (Δ7,8 compound) followed by an apo-rearrangement during which one methyl migrates from C-14 to C-8 and double bond from C-7 to C-14. 相似文献
47.
《液相色谱法及相关技术杂志》2012,35(18):2103-2117
Hypolipidemic agents, E- and Z-guggulsterones, are the biomarker compounds found in the gum-resin exudates of Commiphora mukul. Gum-Resin exudates of six common plants included Mangifera indica, Ficus religiosa, Delonix regia, Acacia nilotica, Abies balsamea, and Commiphora stocksiana and were screened against the said drug by the HPLC method. The developed method was validated for the quantification of E- and Z-guggulsterones in the gum-resin exudates of Commiphora mukul (raw form), guggulipid (ethyl acetate extract of gum-resin,) and its pharmaceutical products (finished form) that are the various components involved in the preparation of pharmaceutical products, from raw materials to finished products. The method involved a simple extraction procedure under sonication. The new method was validated as per the ICH recommended guidelines, including specificity, linearity, precision, accuracy, limit of quantitation, and robustness. The method has a validated quantitation range of 2–65 µg/mL with a precision of ±2% SD, recovery of >99.5% and correlation coefficients >0.999 for both E- and Z-guggulsterones. The statistical analysis proves that the method is repeatable and selective for the estimation of the said drugs and can be used as a routine analytical method and applicable to the different processing components involved in the pharmaceutical preparation from Commiphora mukul resin. Supplemental materials are available for this article. Go to the publisher's online edition of the Journal of Liquid Chromatograhy & Related Technologies to view the free supplemental file. 相似文献
48.
Acharaporn Duangjai Nitra Nuengchamnong Learn-Han Lee Bey-Hing Goh Surasak Saokaew Nungruthai Suphrom 《Natural product research》2019,33(10):1491-1494
Azadirachta indica has long been used in traditional medicine. This study focused on isolation and characterisation of active ingredients in the extract, its fractions (NF-EA, NF-AQ, NF-G) and its effect on the cholesterol absorption activity. The NF-EA fraction was identified by marker compounds by LC-ESI-QTOF/MS. Cholesterol absorption activity was performed by measuring the solubility and size of cholesterol micelles. The intestinal motility was also examined by isolated rat’s ileum to test the contraction. The extract and its fractions consist of flavonoids and phenolic compounds, like quercetin, kaempferol and myricetin. We found that A. indica extract and NF-EA increase cholesterol micelles size, while the extract, NF-AQ, myricetin and quercetin, reduced the solubility of cholesterol in micelles. The extract and quercetin inhibited the contraction induced by KCl up to 29 and 18%, respectively, and also decreased CaCl2-induced contraction. This finding is in support to traditional uses of A. indica as cholesterol-lowering agents and regulator of gastrointestinal motility. 相似文献
49.
Leidy J. Cern-Martínez Andrs M. Hurtado-Benavides Alfredo Ayala-Aponte Liliana Serna-Cock Diego F. Tirado 《Molecules (Basel, Switzerland)》2021,26(8)
Colombian mango production, which exceeded 261,000 t in 2020, generates about 40% of the whole fruit as solid waste, of which more than 50% are seed kernels (over 52,000 t solid by-product); though none is currently used for commercial purposes. This study reports the results of the supercritical carbon dioxide (scCO2) extraction of an oil rich in essential fatty acids (EFAs) from revalorized mango seed kernels and the optimization of the process by the Response Surface Methodology (RSM). In pilot-scale scCO2 experiments, pressure (23–37 MPa) and temperature (52–73 °C) were varied, using 4.5 kg of CO2. The highest experimental oil extraction yield was 83 g/kg (37 MPa and 63 °C); while RSM predicted that 84 g/kg would be extracted at 35 MPa and 65 °C. Moreover, by fine-tuning pressure and temperature it was possible to obtain an EFA-rich lipid fraction in linoleic (37 g/kg) and α-linolenic (4 g/kg) acids, along with a high oleic acid content (155 g/kg), by using a relatively low extraction pressure (23 MPa), which makes the process a promising approach for the extraction of oil from mango waste on an industrial scale, based on a circular economy model. 相似文献
50.
籼稻幼胚组织培养高频率植株再生及其基因转化的研究 总被引：2，自引：0，他引：2
以籼稻品种特青的幼胚作为外植体,研究了激素对愈伤组织诱导及植株再生的影响。ＭＳ＋２,４－Ｄ２ｍｇ／Ｌ作培养基,愈伤组织诱导率达１００％;愈伤组织在ＭＳ＋ＫＴ３ｍｇ／Ｌ＋ＮＡＡ０．５ｍｇ／Ｌ的培养基上,分化频率为６７．３％,在此基础上利用基因枪转化技术,将外源的ｂａｒ基因导入了水稻基因组,转基因植株表现出对除草剂Ｂａｓｔａ很强的抗性。 相似文献