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1.
The purpose of this study is to illustrate, with a controlled example, the influence of raw material variability on the excipient’s functionality during processing. Soluble starch was used as model raw material to investigate the effect of variability on its compaction properties. Soluble starch used in pharmaceutical applications has undergone a purification procedure including washing steps. In this study, a lot of commercially available starch was divided into two parts. One was left intact and the other was subjected to an extra washing step. The two resulting lots were subjected to a series of physical characterization tests typical of those used to qualify raw materials. The two resulting lots gave virtually identical results from the tests. From the physical testing point of view, the two lots can be considered as two equivalent lots of the same excipient. However, when tested for their functionality when subjected to a compaction process, the two lots were found to be completely different. The compaction properties of the two lots were distinctly different under all environmental and processing conditions tested. From the functionality point of view, the two lots are two very different materials. The similar physical testing results but different functionality can be reconciled by considering the surface properties of the powders. It was found that the washing step significantly altered the surface energetic properties of the excipient. The washed lot consistently produced stronger compacts. These results are attributable to the measurably higher surface energy of induced by the additional washing step.  相似文献   

2.
In order to search for radical scavengers which could be used as raw materials for cosmetics, phenyl propanoids (eugenol, isoeugenol, dehydrodieugenol, dehydrodieugenol B and coniferyl aldehyde) were examined for their hydroxyl radical (· OH) scavenging ability. A Fenton system was used to produce -OH. In order to see scavenging by these phenyl propanoids, competition reactions between a spin trap, 5,5-dimethyl-1-pyrroline-N-oxide (DMPO), and these phenyl propanoids for -OH were studied. The relative yield of the spin adduct of -OH (DMPO-OH) was measured by electron spin resonance spectroscopy. The approximate rate constants of the reactions between these phenyl propanoids and -OH estimated by measuring the reduced height of the ESR signals of DMPO-OH were found to be at least in the order of 109 M-1 s-1 (diffusion-controlled). Also, using the TBA tests, the reactions between ·OH and several compounds reactive with ·OH were investigated in the presence of the phenyl propanoids and it was found that the phenyl propanoids compete with such reactive compounds for ·OH. These results indicate that these phenyl propanoids can be used as antioxidants for skin damage perhaps caused by -OH generated by UV-light.  相似文献   

3.
Used frying oil seems to be an economically viable and environmentally attractive alternative for biodiesel production, but the acceptance and successful use of this and other biodiesels obtained from waste materials require careful evaluation of its fuel properties and impurities. Herein, we show that biodiesel made from used frying soybean oil display overall quality comparable to those obtained from the fresh oil as measured by standard parameters of fuel quality such as induction period, acid number, heat of combustion, and iodine value as well as at the molecular level via profiles of intact and oxidized fatty acid methyl esters. These profiles were obtained directly from the biodiesel samples by easy ambient sonic spray ionization mass spectrometry. An artificial antioxidant, N,N??-di-sec-butyl-p-phenylenediamine, was shown to significantly increase the oxidative stability of the used frying oil biodiesel at trace level.  相似文献   

4.
Ibrahim  K. S.  El-Sayed  E. M. 《Neurophysiology》2020,52(2):169-175
Neurophysiology - Parkinson’s disease (PD) is a heterogeneous neurodegenerative disorder, characterized by depletion of dopamine resulted from the death of dopaminergic neurons in the...  相似文献   

5.
In this study we determined oil degradation rates in the North Sea under most natural conditions. We used the heavy fuel oil, Bunker C, the major oil pollutant of the North Sea, as the model oil. Experiments were conducted in closed systems with water sampled during winter and repeated under identical conditions with water collected during summer. No nitrogen or phosphorous was added and conditions were chosen such that neither oxygen nor nutrients, present in the water, would become limiting during the experiments. We detected a fourfold increased degradation rate for water samples taken in summer (18°C water temperature) as compared to water sampled in winter (4°C water temperature). Under the assumption that biodegradation of oil can be regarded as a Michaelis-Menten type kinetic reaction, the kinectic constants Vmax and KM were determined for oil biodegradation at 4°C and 18°C. At both temperatures KM was about 40 ppm, whereas Vmax was 3–4 times higher at 18°C. From both Vmax and the results of fermentation studies, we determined the maximum rates of Bunker C oil degradation in the North Sea as ∼20 g m−3a−1 at 4°C in winter and 60–80 g m−3a−1 at 18°C in summer. Furthermore, while over 25% of the oil was degraded within 6 weeks in summer, only 6.6% of the oil was degraded in winter. A higher incubation temperature in winter (18°C) increased both the rate and the percentage of oil degraded, but degradation did not reach the level obtained during the summer. While these data reflect the oxidation only of the hydrocarbons, we conducted experiments directly in the open sea to determine the contribution of abiotic factors to oil removal. Approximately 42% of the oil was lost within 6 weeks under these conditions in summer and 65% in winter. However, GC-MS analysis of the recovered oil showed no significant change in the alkane pattern that would indicate enhanced degradation. Thus, mainly abiotic factors such as erosion and dispersion rather than degradation were responsible for enhanced oil removal. Especially the high loss during winter can be attributed to frequent storms resulting in greater dispersion. In conclusion, the higher oil degrading potential of the microbial population in the North Sea was represented by a four times faster oil degradation during the summer. In-situ experiments showed that abiotic factors can have an equal (summer) or even higher (winter) impact on oil removal.  相似文献   

6.
Abstract The enrichment of several genes (xylE, nahAcd, todC1C2BA, tmoABCDE, alkB) that encode enzymes responsible for key steps in the degradation of hydrocarbons, and one gene specific to rRNA group I of the genus Pseudomonas, was studied in DNA extracted from a fuel oil–contaminated field site, and in laboratory microcosms (with the exception of alkB). Toluene, ethylbenzene, xylene, and naphthalene concentrations were related to the extent of hybridization of the genes in the field studies. Significant differences were observed in the extent of hybridization of some of the genes between contaminated and noncontaminated samples. In the microcosm studies, gasoline at rates ranging from 0.5 mg to 125 mg gasoline/g of soil as applied to soils, and the changes in hybridization intensity of these genes monitored with time. The lower threshold of gene enrichment of these genes in response to gasoline addition was below 0.5 mg/g soil. Small increases were observed at the 0.5-mg exposure level, but hybridization intensity quickly decreased to levels below detection 6–8 days after addition of the gasoline. A dose-response effect was observed from treatments with gasoline concentrations ranging from 0.5 to 35 mg/g soil. Inhibition by toxic components in gasoline was observed at 75 and 125 mg/g soil levels. Hybridization of the Pseudomonas group 1 probe to field DNA was not significantly enriched in the contaminated field site, although these sequences were enriched in the microcosm studies. Among the genes tested, xylE was the most sensitive indicator of low levels of fuel oil contamination. Received: 23 July 1996; Accepted 9 October 1996  相似文献   

7.
Although well known for delivering various pharmaceutical agents, liposomes can be prepared to entrap gas rather than aqueous media and have the potential to be used as pressure probes in magnetic resonance imaging (MRI). Using these gas-filled liposomes (GFL) as tracers, MRI imaging of pressure regions of a fluid flowing through a porous medium could be established. This knowledge can be exploited to enhance recovery of oil from the porous rock regions within oil fields. In the preliminary studies, we have optimized the lipid composition of GFL prepared using a simple homogenization technique and investigated key physico-chemical characteristics (size and the physical stability) and their efficacy as pressure probes. In contrast to the liposomes possessing an aqueous core which are prepared at temperatures above their phase transition temperature (Tc), homogenization of the phospholipids such as 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) or 1,2-distearoyl-sn-glycero-3-phosphocoline (DSPC) in aqueous medium below their Tc was found to be crucial in formation of stable GFL. DSPC based preparations yielded a GFL volume of more than five times compared to their DPPC counter part. Although the initial vesicle sizes of both DSPC and DPPC based GFL were about 10 μm, after 7 days storage at 25°C, the vesicle sizes of both formulations significantly (p < 0.05) increased to 28.3 ± 0.3 μm and 12.3 ± 1.0 μm, respectively. When the DPPC preparation was supplemented with cholesterol at a 1:0.5 or 1:1 molar ratio, significantly (p < 0.05) larger vesicles were formed (12–13 μm), however, compared to DPPC only vesicles, both cholesterol supplemented formulations displayed enhanced stability on storage indicating a stabilizing effect of cholesterol on these gas-filled vesicles. In order to induce surface charge on the GFL, DPPC and cholesterol (1: 0.5 molar ratio) liposomes were supplemented with a cationic surfactant, stearylamine, at a molar ratio of 0.25 or 0.125. Interestingly, the ζ potential values remained around neutrality at both stearylamine ratios suggesting the cationic surfactant was not incorporated within the bilayers of the GFL. Microscopic analysis of GFL confirmed the presence of spherical structures with a size distribution between 1–8 μm. This study has identified that DSPC based GFL in aqueous medium dispersed in 2% w/v methyl cellulose although yielded higher vesicle sizes over time were most stable under high pressures exerted in MRI.  相似文献   

8.
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10.
Investigation has been carried out on the constituents of the monoterpene fraction of geranium oil from Pelargonium roseum Bourbon and, besides well-known components of the oil, some new components such as epoxylinalool, methyl heptenone, myrcene, limonene, p-cymene, citral and 2,2,6-trimethyl-6-vinyl-tetrahydropyran which was confirmed by deriving to cinenic acid, have been identified.  相似文献   

11.
Oleogels were prepared from extra virgin olive oil, corn oil, sunflower oil, and flaxseed oil with a mixture of β-sitosterol and stearic acid (Sit1:SA4, w/w) at concentrations of 15 and 20 g/100 g oil. The prepared oleogels were characterized by different methods to study the influence of oil type on the oleogel properties. The oil type influenced the colour and appearance of the oleogel. The flaxseed oil based oleogel showed lower oil loss and higher firmness than those of other oils based oleogels. The increase of gelator mixture from 15 to 20 g/100 g oil reduced the oil loss and improved the firmness of oleogel samples. The microscopy and small-angle x-ray scattering analyses showed different microstructures and crystallographic reflections for oleogels prepared from different oil types. Also, the oil type and concentration of gelator mixture influenced the melting and crystallization enthalpies of oleogel. Furthermore, different oils based oleogels showed varying values of viscosity, storage modulus (G’), and loss modulus (G”). Therefore, it can be concluded that the oil type and concentration of gelator influence the functional properties of oleogel and the flaxseed oil resulted in oleogel with good properties compared with other oils used in the study.  相似文献   

12.
Turnip oil (TO; Raphanus sativus L.) produces seeds that contain around 26 wt% of inedible base stock that are suitable as a potential feedstock for biodiesel production. A turnip oil methyl ester (TME) was prepared from acid-catalyzed pretreated TO in an effort to evaluate important fuel properties of turnip oil-based biodiesel, such as kinematic viscosity, cloud point, pour point (PP), cold filter plugging point, acid value, oxidative stability and lubricity. A comparison was made with soybean oil methyl esters (SME) as per biodiesel fuel standards such as ASTM D6751 and EN 14214. TME was characterized using FTIR, HPLC and 1H NMR. Except PP property, SME displays superior fuel properties compared to TME. Blends (B5 and B20) of TME in ultra-low sulphur diesel fuel (ULSD) were also assessed for the aforesaid fuel properties and compared to an analogous set of blends of soybean oil methyl ester in ULSD as per petro diesel fuel standards such as ASTM D975 and D7467. TME B5 blends in ULSD displayed improved PP property in comparison to neat ULSD and blends of SME in ULSD. It was demonstrated that the B5 and B20 blends of TME in ULSD had acceptable fuel properties as per ASTM D975 (for B5 blend) and ASTM D7467 (for B20 blend). In summary, turnip oil has potential as an alternative, non-food feedstock for biodiesel production.  相似文献   

13.
To explore the underlying mechanisms for the protective effects of garlic oil (GO) against nitrosodiethylamine (NDEA)-induced hepatocarcinoma, 60 male Wistar rats were randomized into 4 groups (n=15): control group, NDEA group, and two GO plus NDEA groups. The rats in GO plus NDEA groups were pretreated with GO (20 or 40 mg/kg) for 7 days. Then, all rats except those in control group were gavaged with NDEA for 20 weeks, and the rats in GO plus NDEA groups were continuously administered with GO. The results showed that GO co-treatment significantly suppressed the NDEA-induced increases of alpha fetal protein (AFP) level in serum, nuclear atypia in H&E staining, sirius red-positive areas and proliferating cell nuclear antigen (PCNA) expression. The molecular mechanisms exploration revealed that the protein levels of phosphatidylinositol 3 kinase (PI3K)-p85, PI3K-p110, total AKT, p-AKT (Ser473) and p-AKT (Thr308) in the liver of NDEA group rats were higher than those in control group rats. In addition, NDEA treatment induced IκB degradation and NF-κB p65 phosphorylation, and up-regulated the protein levels of downstream pro-inflammatory mediators. GO co-treatment significantly reversed all the above adverse effects induced by NDEA. These results suggested that the protective effects of GO against NDEA-induced hepatocarcinoma might be associated with the suppression of PI3K- AKT-NF-κB pathway.  相似文献   

14.
Eighty-one constituents were newly identified from the oil of Mentha piperita L., including a new keto-alcohol, (?)-mintlactone and (+)-isomintlactone. They were determined by spectral data and syntheses to be 4-hydroxy-4-methyl-2-cyclohexen-1-one (8), (6R, 7aR) (10) and (6R, 7aS)-3,6-dimethyl-5,6,7,7a-tetrahydro-2(4H)-benzofuranone (11), respectively.  相似文献   

15.
We searched for quantitative trait loci (QTL) associated with the palm oil fatty acid composition of mature fruits of the oil palm E. guineensis Jacq. in comparison with its wild relative E. oleifera (H.B.K) Cortés. The oil palm cross LM2T x DA10D between two heterozygous parents was considered in our experiment as an intraspecific representative of E. guineensis. Its QTLs were compared to QTLs published for the same traits in an interspecific Elaeis pseudo-backcross used as an indirect representative of E. oleifera. Few correlations were found in E. guineensis between pulp fatty acid proportions and yield traits, allowing for the rather independent selection of both types of traits. Sixteen QTLs affecting palm oil fatty acid proportions and iodine value were identified in oil palm. The phenotypic variation explained by the detected QTLs was low to medium in E. guineensis, ranging between 10% and 36%. The explained cumulative variation was 29% for palmitic acid C16:0 (one QTL), 68% for stearic acid C18:0 (two QTLs), 50% for oleic acid C18:1 (three QTLs), 25% for linoleic acid C18:2 (one QTL), and 40% (two QTLs) for the iodine value. Good marker co-linearity was observed between the intraspecific and interspecific Simple Sequence Repeat (SSR) linkage maps. Specific QTL regions for several traits were found in each mapping population. Our comparative QTL results in both E. guineensis and interspecific materials strongly suggest that, apart from two common QTL zones, there are two specific QTL regions with major effects, which might be one in E. guineensis, the other in E. oleifera, which are independent of each other and harbor QTLs for several traits, indicating either pleiotropic effects or linkage. Using QTL maps connected by highly transferable SSR markers, our study established a good basis to decipher in the future such hypothesis at the Elaeis genus level.  相似文献   

16.
Phytoremediation is a nondestructive, cost-effective in-situ technology to clean up contaminated soils. In the case of contamination with petroleum hydrocarbons, plants enhance microbial degradation of the contaminant in the rhizosphere. The potential of this technology for the tropics should be high due to prevailing climatic conditions favoring plant growth and stimulating microbial activity. Investigations of the potential of tropical plants for phytoremediation, however, are scarce. The present work studied two grasses and six legumes from the eastern savannah of Venezuela on their reaction to crude oil contamination in soil. Results shall help to identify plants with a potential for phytoremediation and subsequent studies. Seedling emergence and biomass production were determined for plants growing in soil contaminated with 0%, 3%, and 5% heavy crude oil. Contamination had, in general, a tendential but not significant negative influence on seedling emergence. Dry matter production was reduced by only a few percent to up to 85%. Furthermore, in some legumes inhibition of nodulation was observed. The grass Brachiaria brizantha and the legumes Centrosema brasilianum and Calopogonium mucunoides are promising for phytoremediation because in contaminated soil they combined high seedling emergence with least affected biomass production. Since they are cultivated forage/soil cover species also in other regions of the tropics, their potential for phytoremediation of petroleum contaminated soils extends beyond Venezuela.  相似文献   

17.
18.

Background

The extent to which Alberta oil sands mining and upgrading operations have enhanced delivery of bitumen-derived contaminants via the Athabasca River and atmosphere to the Peace-Athabasca Delta (200 km to the north) is a pivotal question that has generated national and international concern. Accounts of rare health disorders in residents of Fort Chipewyan and deformed fish in downstream ecosystems provided impetus for several recent expert-panel assessments regarding the societal and environmental consequences of this multi-billion-dollar industry. Deciphering relative contributions of natural versus industrial processes on downstream supply of polycyclic aromatic compounds (PACs) has been identified as a critical knowledge gap. But, this remains a formidable scientific challenge because loading from natural processes remains unknown. And, industrial activity occurs in the same locations as the natural bitumen deposits, which potentially confounds contemporary upstream-downstream comparisons of contaminant levels.

Methods/Principal Findings

Based on analyses of lake sediment cores, we provide evidence that the Athabasca Delta has been a natural repository of PACs carried by the Athabasca River for at least the past two centuries. We detect no measureable increase in the concentration and proportion of river-transported bitumen-associated indicator PACs in sediments deposited in a flood-prone lake since onset of oil sands development. Results also reveal no evidence that industrial activity has contributed measurably to sedimentary concentration of PACs supplied by atmospheric transport.

Conclusions/Significance

Findings suggest that natural erosion of exposed bitumen in banks of the Athabasca River and its tributaries is a major process delivering PACs to the Athabasca Delta, and the spring freshet is a key period for contaminant mobilization and transport. This baseline environmental information is essential for informed management of natural resources and human-health concerns by provincial and federal regulatory agencies and industry, and for designing effective long-term monitoring programs for the lower Athabasca River watershed.  相似文献   

19.
The chemical components of different genera and species of Taxaceac have been analyzed in order to provide the data for discussion of the systematic position of this family. A characteristic component kayaflavone from the leaves of Torreya grandis cv. ‘Merrillii' has been reported in our previous paper. Recently we have obtained also a new diterpene torreyagrandate from the leaves of this species. The present paper deals with our preliminary study on essential oil composition of the leaves in the same species. 26 components have been identified. Three of them, limonene, α-pinene and δ-3-carene, are the main ones, with their contents being 44.24%, 20.75% and 4% respectively. The essential oilalso contains torreyol which is a characteristiccomponent in this species.  相似文献   

20.
Two successive randomized trials examined the effect of an increased intake of fatty fish, or the use of fish oil supplements, in reducing mortality in men with heart disease. The Diet and Reinfarction Trial (DART) was conducted in 2033 men who were recovering from acute myocardial infarction (MI). Those who were advised to eat fatty fish (or who opted to take fish oil capsules instead) had a 29% reduction in all-cause mortality over the following two years compared with those not so advised. The effect appeared in the first few months of the trial. The Diet and Angina Randomized Trial (DART 2) involved 3114 men with stable angina. Advice to eat fatty fish did not reduce mortality, and taking fish oil capsules was associated with a higher risk of cardiac and sudden death. The adverse effects of fish or fish oil were restricted to men not taking β-blockers or dihydropyridine calcium-channel blockers, and were greater in those taking digoxin. Evidence from other sources strongly suggests an anti-arrhythmic action of fish oil, particularly after MI or in the presence of acute ischemia. The apparently conflicting results of the two trials may reflect different actions of n-3 fatty acids in acute and chronic conditions, together with different effects of eating fish and taking fish oil capsules. A mechanism is proposed that could account for these findings.  相似文献   

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