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991.
目的研究温度和酸的种类对人参总皂苷酸水解的影响,从而确定人参二醇的最佳制备工艺。方法以人参总皂苷为原料,在规定温度分别以10%3种酸、50%乙醇溶液为溶剂,水浴回流水解4h,水解液回收乙醇后用氯仿萃取,氯仿层合并回收氯仿,残渣用甲醇溶解,用薄层扫描仪测定含量。结果80℃时,盐酸、硫酸和硝酸人参二醇得率分别为10.15%、8.81%和16.69%;90℃时,分别为1.80%、11.02%和2.14%;100℃时分别为0.47%、13.70%和2.35%。结论盐酸和硝酸温度越高,人参二醇含量反而降低;硫酸温度越高,人参二醇得率越高且纯度高。因此,人参二醇最佳的制备方法应为100℃、10%硫酸水解。 相似文献
992.
Hakan Basak K. Mesut Çimrin Metin Turan Ekrem Ozlu 《Communications in Soil Science and Plant Analysis》2019,50(3):350-361
Mycorrhiza has attracted interest as one of the microorganisms that increase a crop’s salt stress tolerance. This study was conducted to determine the impacts of mycorrhiza inoculation and applying salt at different ratios on the yield of peppers and amino acid concentrations. The study was conducted in greenhouse conditions on loamy soils with four salt treatments, two mycorrhiza inoculations and a control in a complete randomized block design. The present study indicated that salt treatment alone was significantly correlated with crop stem and root amino acid concentrations, RWC% and leaf sizes, whereas applying mycorrhiza showed a positive relationship to stem height, stem and root wet weight, and root amino acids but led to a decloine in root serine and glutamine, and stem amino acid and glutamine. In conclusion, inoculating with mycorrhiza was observed to make a positive contribution to salt stress tolerance at different levels in almost all the parameters examined. 相似文献
993.
Awtar Singh A. P. Singh T. J. Purakayastha 《Archives of Agronomy and Soil Science》2019,65(9):1302-1315
Application of biochar to soil has increased considerably during recent years because of its effectiveness as a soil amendment causing beneficial effects on soil health. However, the effects have been reported to vary and depend upon types of feedstock and pyrolysis conditions during biochar production. Therefore, characterization of biochar is extremely important for its efficient utilization as a soil amendment. In the present study, biochar was prepared from agro-industrial by-products (rice husk and sugarcane bagasse) and weeds (Parthenium and Lantana) under similar pyrolysis conditions. Lantana biochar (LBC) showed the highest pH (10.4) while the lowest value (8.5) being recorded in rice husk biochar (RHBC). The energy-dispersive X-ray spectroscopy (EDS) analysis indicated that LBC and Parthenium biochar (PBC) were superior with respect to potassium (K) content than sugarcane bagasse biochar (SBBC) and RHBC. The Fourier-Transform Infrared Spectroscopy (FTIR) study exhibited the existence of different functional groups in biochar. All the biochar treated soils showed significantly higher microbial activities with different degrees. Application of LBC and PBC at 4.50 g kg?1 soil significantly increased K availability in soil. Lantana biochar and PBC amended the soil at 9 g kg?1 significantly increased the soil pH thus makes these biochar as potential liming materials. 相似文献
994.
[目的]优选β-环糊精包合γ-亚麻酸的最佳工艺。[方法]采用BOX-Behnken设计和响应曲面分析优选包合的最佳工艺,并采用差示扫描量热分析及X-射线衍射对包合物进行定性分析。[结果]β-环糊精包合γ-亚麻酸的最佳工艺条件为:β-环糊精与γ-亚麻酸的物质的量比6.47∶1、温度51.15℃、包合时间2.03h,在该条件下包合率达91.51%。定性分析表明γ-亚麻酸与β-环糊精确实形成了包合物,其包合物的结构与简单混合物的结构有明显不同,已构成新的固体相。[结论]该研究可有效地减少工艺操作的盲目性,为进一步的放大生产提供依据。 相似文献
995.
水稻矮缩病毒对3种内源激素含量及代谢相关基因转录水平的影响 总被引:2,自引:0,他引:2
本文以抗病品种宜香2292(Oryzas ativa L. ssp. indica cv. Yixiang 2292)为材料,采用高效液相色谱技术(HPLC)和Real-time PCR技术研究了水稻矮缩病毒(Rice dwarfvirus,RDV)胁迫下水稻内源赤霉素(GA3)、生长素(IAA)和脱落酸(ABA)的动态变化。结果表明,受RDV侵染后,病株体内GA3含量显著低于健株,在显症后的第1d和第10d最为明显,分别较健株低6.28和5.92倍;IAA含量呈现波动变化,但病株体内的IAA含量始终较健株低,在显症后的10d最为明显,比健株低3.58倍;与GA3和IAA相反,病株体内ABA的含量始终高于健株,显症后的第1d和第13d最为明显,分别较健株高2.29和2.84倍。Real-time PCR定量检测了植物内源激素相关基因mRNA的表达,结果显示,GA3代谢相关的氧化还原酶基因表现为下调,而IAA和ABA代谢相关的Cullin-1和P-glycoprotein1基因表现出不同程度的上调。以上结果表明:水稻矮缩病的症状表现可能与病株体内的植物内源激素失调有关。 相似文献
996.
In this study, we investigated the effect of ascorbic acid (AA) administration on goat excitability due to transportation. Ten goats administered AA (p.o.) at 100 mg/kg of body weight before transportation served as the experimental group, and seven goats administered only 10ml/kg of sterile water (p.o.) served as controls. Excitability scores were recorded for each goat; when weighed, before, immediately after, and 3 h after 8 h of transportation. A score of one to four was allocated to each goat; higher scores represent greater excitability. Immediately after transportation, excitability scores decreased significantly, especially those of control goats (p < 0.001). At 3 h post-transportation, the excitability scores of animals in the experimental group were not significantly (p>0.05) different from their pre-transportation normal values, whereas those of control goats were significantly lower (p < 0.01). The correlation i.e. the relationship between excitability score values and percent excitability (percentage of goat with particular excitability score) for different excitability score group 3 h post-transportation was positive and highly significant (p < 0.001), in both experimental and control goats. Our results indicate that road transportation induces considerable stress (depression) in goats as evidenced by a lower excitability score post-transportation. Moreover, the administration of AA pre-transportation facilitated the transition from a state of depression to excitation. In conclusion, AA administration to animals prior to transportation may ameliorate the depression often encountered after road transportation. 相似文献
997.
998.
999.
Routine agricultural practices are heavily dependent on the use of surfactants, many of which are toxic to humans and detrimental to the environment. In proof of concept work we have previously shown the potential of nanostructured liquid crystalline particles (NLCP) to safely interact with plant leaf cuticular surfaces with minimal impact on epicuticular waxes. Here we demonstrate the use of NLCP to effectively deliver the auxin herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) to plant leaves in laboratory and field studies. In the laboratory, the physiological stress responses of lupin, Lupinus angustifolius (L.) (Fabaceae) towards NLCP spray applications were shown to be much reduced in comparison with application of two common surfactants. Phytotoxicity assays of 2,4-D loaded NLCP were used to validate the herbicidal effects on Arabidopsis thaliana (L.) Heynth. (Brassicaceae) and established a similarity with that of surfactant assisted 2,4-D delivery when tested at a concentration of 0.1%. Field trials were conducted to test the efficacy of NLCP-assisted delivery of 2,4-D in comparison with commercial surfactants for the control of the invasive weed wild radish, Raphanus raphanistrum (L.) (Brassicaceae), in wheat, Triticum aestivum (L.) (Poaceae) crop fields. Compared against Estercide 800, a commercially available 2,4-D formulation, NLCP assisted delivery of 2,4-D was effective at low concentrations of 0.03% and 0.06%. The crop yield remained similar for all the tested concentrations and formulations of 2,4-D loaded NLCP and Estercide 800. This is the first report to directly show that, as an alternative to conventional methods, NLCP can be used under both laboratory and field conditions to successfully delivery an agrochemical. 相似文献
1000.
Traugott J. Scheytt Petra Mersmann Elzbieta Rejman-Rasinski Anja These 《Journal of Soils and Sediments》2007,7(2):75-84
Background, Aim and Scope
One of the first occurrences of pharmaceutically active compounds in groundwater was reported from the sewage irrigation farms
south of Berlin. At these sewage irrigation farms treated sewage effluent passed the soil and unsaturated zone before reaching
the aquifer. Clofibric acid was detected in pore water from soils of those sewage irrigation farms in concentrations between
65 ng/L and 1430 ng/L. The aim of this study was to investigate the transport behavior of regularly detected clofibric acid,
diclofenac, ibuprofen, and propyphenazone under conditions comparable to those at the sewage irrigation farms in a multiple
compound sand column laboratory experiment.
Materials and Methods
Sediment column experiments were conducted to study the transport of pharmaceuticals in the unsaturated zone. The migration
was measured in fine to medium grained sand and leaching solution containing 1 mg/L of pharmaceutically active compounds and
61 mg/L of the tracer lithium chloride (LiCl). For the analysis of the pharmaceutical compounds the water samples were adjusted
to a pH value of 2 and then extracted by solid-phase extraction (SPE). Before extraction, the samples were spiked with a surrogate
standard for analytical quality control. The sample extracts were analyzed by capillary gas chromatography-mass spectrometry
(GC-MS) with selected ion monitoring (SIM). Depending on the sample volume (100 to 200 mL) and the matrix, the limits of detection
were between 1 and 10 ng/L, and the limits of quantitation were between 5 and 25 ng/L. Analysis for calcium, magnesium and
lithium were carried out using a 'Trace Scan' ICP-AES from Thermo Jarrel Ash. Sodium, potassium, iron and manganese were analyzed
using a Philips PU 9400 flame AAS. Analysis of anions was performed on a Dionex ion chromatograph DX 120.
Results
At the sewage irrigation farms the average concentrations of clofibric acid in the unsaturated zone declined from higher values
near ground surface (480 ng/L) to lower values near the groundwater table (65 ng/L). From the pharmaceuticals analyzed only
clofibric acid, primidone and propyphenazone could be analyzed in the first (upper) aquifer at the sewage irrigation farms.
All other pharmaceuticals could neither be detected in the first aquifer nor in the deeper aquifers. Breakthrough curves from
soil column experiments revealed no transformation and no retardation for clofibric acid, whereas transformation of diclofenac
was so high (79%) that no retardation factor could be calculated. Ibuprofen was significantly transformed (37%), transformation
of propyphenazone (17%) was quite low and retardation (Rf = 2.05) was in the range of previously conducted column experiments.
Discussion
The results confirm previously conducted experiments with clofibric acid where this compound was identified as highly mobile
and persistent. The results that diclofenac and ibuprofen are significantly transformed where unexpected as other studies
exhibited much lower transformation under saturated conditions at least for diclofenac. However, lower pH values and higher
oxygen contents in the unsaturated zone compared to the aquifer may explain this observed high transformation of these compounds
at the column experiments.
Conclusions
We conclude that irrigation with sewage effluent containing the compounds used in our experiments will lead to an input into
groundwater of clofibric acid, whereas diclofenac and ibuprofen will most likely be transformed during the passage. Propyphenazone
will be retarded but will most likely occur in groundwater. These results from the column experiments coincide very well with
the occurrence of the pharmaceuticals clofibric acid, primidone, and propyphenazone in the first aquifer.
Recommendations and Perspective :
The results underline the need to study the sorption of pharmaceuticals on various materials. e.g. organic matter, surfaces
at pH values occurring in the unsaturated zone. Future field studies will also include the investigation of desorption behavior
in the unsaturated zone. 相似文献