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1.
Bluefin tuna (Thunnus thynnus) is consumed in substantial amounts by humans. However, little has been reported on the fatty acid composition of bluefin body oil and on the isomeric structures of the unsaturated fatty acids. Because of the probable nutritional significance of unsaturated fatty acids, the present work was undertaken as an introductory study of the composition and structure of the fatty acids of tuna. The fatty acid composition of the light and dark meats from three bluefin tuna was determined by gas-liquid chromatography. A wide variety of saturated and polyunsaturated fatty acids were present in the oil from the meat of these speciments. the monoemoic fatty acid fraction, which comprises 34% of the total fatty acids was isolated and the isomers determined. Isomers found werecis-9-hexadecenoic acid,cis-9-octadecenoic acid,cis-11-octadecenoic acid,cis-9-eicosenoic acid,cis-11-eicosenoic acid,cis-11-docosenoic acid, andcis-13-docosenoic acid. Division of Industrial Research, U.S. Fish and Wildlife Service, Department of the Interior.  相似文献   

2.
Maximum advantage of certain fish species captured with shrimp, at present not fully utilized, constitutes a necessity in Venezuela. The purpose of this research work was to evaluate the stability of three of those fish species: bagre, cunaro and caballa, based on the changes that might occur in their fat content. This was done by comparing both the edible part of the whole fish, as well as the deboned flesh of each of them. Evaluation of the changes was performed by means of the acid and peroxide indices, with previous fat extraction, and the thiobarbituric acid (TBA) index. On the other hand, the fatty acids profile of the three species studied was determined by gas chromatography. According to our findings, the greater alteration was detected in the deboned sample, obtaining the highest TBA and acidity index values of all species, on the third month of storage; then a reduction of these values was observed. On the other hand, the peroxide index presented heterogeneous values in the three species analyzed through their storage period. The predominant fatty acids were: palmitic (16:0) among the saturated, and oleic (18:1) among the unsaturated. A greater proportion of unsaturated fatty acids was found in the three species. An increment of these in the deboned sample with respect to the whole fish, was also observed.  相似文献   

3.
The objective of the present work was to study functional and thermal properties of reineta (Brama australis) frozen meat, analysed by water retention capacity (WRC), gel forming capacity (GFC), texture, emulsifying capacity and differential scanning calorimetry (DSC). For this study, reineta fillets were obtained and extracted by the same conditions, and cutted, packaged, frozen and stored at -18 degrees C and -30 degrees C for 7 months. The results obtained, showed that there were no signifficant differences in the responses to thermal treatment for all the specimens. For samples frozen at -18 degrees C and -30 degrees C, the protein contents were 23.5 + 0.0 and 25.4 + 1.0%, respectively. The WRC values were 0.45 + 0.1 and 1.59 +/- 0.0 g water/g protein, respectively. The gel forming capacity was only present in the fresh samples, whereas the frozen stored ones only form protein aggregates. The emulsifying capacity was between 960 and 1400 g oil / g protein, and the storage time increased this value. The miosin denaturation temperature (Td) and denaturation enthalpy (?H), obtained by DSC, fluctuated between 39.2 +/- 0.5 to 44.8 +/- 0.8 degrees C and 1.12 +/- 0.3 to 0.52 +/- 0.2 J/g, respectively. The actina values were between 71.0 +/- 0.6 to 75.3 +/- 0.5 degrees C and between 0.5 +/- 0.1 to 0.7 +/- 0.1 J/g. Cooperativity decreased as the storage time increased. This is showing a certain degree of protein displacement. The values found by thermal analyses showed a direct relationship with the functional properties, both decreasing with storage time.  相似文献   

4.
This work presents the study of blends formed by a substituted polyaniline (PAni), poly(2,5-dimethoxy aniline) (PDMA), and the fluoropolymers poly(vinylidene fluoride) (PVDF) and poly(tetrafluoroethylene-co-vinylidene fluoride-co-propylene) (co-PTFE). PDMA was electrochemically synthesized from monomer 2,5-dimethoxy aniline (DMA) onto stainless steel surfaces. The polymers and the ternary blends were dissolved in N,N-dimethyl formamide and were deposited onto polished stainless steel plates. Thermal analysis (differential scanning calorimetry (DSC) and thermogravimetric analysis (TG)) and atomic force microscopy (AFM) were used in order to evaluate the properties of the materials. Ternary blends with good adhesion properties and thermal stability (with degradation over 400 °C) were obtained. Porous morphology with indication of PVDF enrichment on surface was observed. Preliminary open circuit potential (OCP) test showed an increase in this potential in the blends, compared with uncoated stainless steel. Therefore, blends with phase separation and very promising new protective properties were produced. Co-PTFE guarantees good adhesion, PDMA the special corrosion protection, and both fluoropolymers contribute to the large thermal stability.  相似文献   

5.
Synthesis and spectral studies of methyl 10-(1,3,2-oxazaphospholidin-2-one)undecanoate and methyl 10-(1,3,2-diazaphospholidin-2-one)undecanoate are reported. These fatty products were obtained in excellent yields when methyl 10-hydroxyundecanoate was reacted with phosphorus oxychloride, and the resultant intermediate was treated with aminoethanol and ethylenediamine in two different reactions.  相似文献   

6.
新型含磷化合物膦菲的开发与应用   总被引:4,自引:0,他引:4  
介绍了新型含磷化合物膦菲的性能、合成方法及其在热塑性塑料、聚氨酯,聚酯中作为耐热阻燃剂的应用,介绍由HCA(商品名)、马来酸酐、乙二醇反应制备阻燃聚酯的方法。  相似文献   

7.
We have conducted high pressure-high temperature (HPHT) diamond synthesis experiments at the conditions of growth of superdeep diamonds (10-20 GPa), equivalent to the transition zone, using MgCO3 carbonate (oxidising) and FeNi (reducing) solvent catalysts. High rates of graphite-diamond transformation were observed in these short duration experiments (20 min). Transformation rates were higher using the metallic catalyst than in the carbonate system. High degrees of carbon supersaturation at conditions significantly above the graphite-diamond stability line, led to a high nucleation density. This resulted in the growth of aggregated masses of diamond outlined by polygonised diamond networks, resembling carbonado. Where individual crystals are visible, grown diamonds are octahedral in the lower pressure experiments (≤ 10 GPa in MgCO3 and ≤ 15 GPa in FeNi) and, cubo-octahedral at higher pressure. All grown diamonds show a high degree of twinning. The diamonds lack planar deformation features such as laminations or slip planes, which are commonly associated with natural superdeep diamonds.  相似文献   

8.
This paper reports on the mechanical and high pressure tribological properties of nanocrystalline (nc-) Ti(N,C)/amorphous (a-) C:H deposited, using low temperature (~ 200 °C) DC reactive magnetron sputtering. The mechanical properties are affected by the nc-Ti(N,C)/a-C:H phase fraction ratio. For increasing C contents (from 31 to 47 at.%) an increase of the a-C:H phase content and a degradation of the nanocrystalline phase occurs leading to a reduction in nanoindentation hardness (H) values (from 15 to 9 GPa) and reduced modulus (Er) values (from 150 to 80 GPa). A strong correlation between H/E ratio and wear performance was exhibited by the coatings. The synthesized coatings survived up to 100 m sliding distance when tested using pin-on-disc sliding configuration at > 4.5 GPa contact pressures and the measured friction coefficient values were similar for all films (μ  0.21–0.25).  相似文献   

9.
部分醇解的聚乙烯醇纤维结构性能初探   总被引:5,自引:0,他引:5  
对较低聚合度的聚醋酸乙烯进行醇解,得到一系列不同醇解度的聚乙烯醇,经纺丝拉伸后,得到不同醇解度、不同拉伸倍数的聚乙烯醇纤维。用FT-IR、DSC和强力仪等研究了醇解度和拉伸倍数对纤维结构性能的影响。结果表明,部分醇解的聚乙烯醇有利于降低拉伸中的氢键作用,提高易拉伸性。  相似文献   

10.
《Ceramics International》2022,48(24):36655-36669
In this study, a series of ZrCrW(C)N multilayer coatings with various transition layers were deposited on AISI304 stainless steel using cathodic vacuum-arc deposition in N2–C2H2 gas mixture. The tribological behaviors of sliding against Al2O3 balls under dry friction and lubricant conditions were investigated using a reciprocating tribometer. The results demonstrated that the ZrCrW(C)N coatings comprised (Zr, Cr, W) (C, N) crystallites and an amorphous carbon phase. It possessed a nano-hardness of 35.4 GPa and an elastic modulus of 417.7 GPa. The friction coefficient of the coating was reduced by 14% compared to that of the 304 matrices, and the wear mechanism changed from adhesive wear to slight abrasive wear under the lubrication steady state. Under dry friction conditions, the ZrCrW(C)N coatings with the entire CrWN transition layer exhibited wear rates of 1.27 ± 0.04 × 10?8 mm3 (N m)?1, which were one order of magnitude lower than that of the 304 steel. Compared with the untreated AISI304 stainless steel, the ZrCrW(C)N coating exhibits excellent mechanical and tribological properties under lubricated and dry friction conditions, which are crucial for engineering applications.  相似文献   

11.
Partially fluorinated poly(fluorenyl ether ketone)s with different degree of sulfonation were successfully synthesized by the sulfonation of the designed parent polymer. The sulfonation took place only at the specific (2, 7)-position on the fluorenyl groups due to the positions adjacent to the ether bond occupied by methyl groups. The sulfonated polymers are soluble in common organic solvents and can readily be cast into tough and smooth films from their solutions. The properties of proton conductivity, water uptake, thermal and oxidative stability for the membranes were investigated. It was found that the oxidative stability of the membrane decreased with increasing the degree of sulfonation. However, the partially fluorinated membrane with high degree of sulfonation exhibited better oxidative stability compared to the non-fluorinated analogy with low degree of sulfonation. The proton conductivity of the membranes increased with increasing the degree of sulfonation and temperature. Moreover, the membranes also showed good thermal and hydrolytic stabilities.  相似文献   

12.
The central role of protein kinase C (PK-C) in cellular signal transduction has established it as an important therapeutic target for cancer and other diseases. We have developed a series of 4,4-disubstituted-gamma-butyrolactones, which contain a constrained glycerol backbone (DAG-lactones) and behave as potent and selective activating ligands of PK-C with affinities that approach those of the structurally complex natural product agonists, such as the phorbol esters. This Account traces the design and construction of these molecules. Initially, we examined the consequences of reducing the entropic penalty associated with the transformation of a DAG into a DAG-lactone. Then, using molecular modeling to extend insights arising from the newly solved crystal structure of a C1 domain complexed with phorbol ester, we incorporated amino acid-specific branched hydrophobic chains to provide a new generation of DAG-lactones that have the capacity to bind to PK-C with low nanomolar affinity. Depending on the specific pattern of hydrophobic substitution, some DAG-lactones are able to induce selective translocation of individual PK-C isozymes to different cellular compartments, and since the specific nature of these hydrophobic interactions influences biological outcome, some of these compounds exhibit cell-specific antitumor activity. The ability to direct specific PK-C isozyme translocation with sets of structurally simple, yet highly potent molecules provides a powerful tool for engineering a plethora of molecules with novel biological functions.  相似文献   

13.
The self-assembly behavior, spectroscopic properties and stability of C.I. Basic Violet 10 (Rhodamine B) were investigated at a relatively high concentration. Rod-like dye nanocrystals could be formed by tuning various THF/H2O volume ratios, leading to increased fluorescence intensity. TEM, zeta-potential measurement and selected-area electron diffraction patterns indicated that the dye nanorods were successfully encapsulated within a silica layer using a sol–gel process. The ensuing silica-coated, dye nanorods exhibited increased fluorescence intensity, non-leachability in polar solvents and high photostability.  相似文献   

14.
60℃下,在体积比为1∶1的乙醇水溶液中,采用常规溶液法合成了钕(Nd)-氨基酸-邻菲啰啉三元配合物。利用配合滴定、摩尔电导、红外光谱(IR)、热重-差热分析(TG-DTG)、紫外光谱(UV)和荧光光谱(FS)等分析手段对配合物的组成和光学等性质进行了分析与表征,推测系列配合物的化学组成为:[Nd(Amino)3Phen]Cl3.3H2O。通过抑菌实验对配合物的生物活性进行了研究。结果表明,组氨酸的羧基氧原子和邻菲啰啉的氮原子均与Nd3+配位,且配合物对大肠杆菌、枯草芽孢杆菌以及金黄色葡萄球菌有较好的抑菌效果。  相似文献   

15.
以20(S)-喜树碱(6)为原料,经氧化,光反应重排,制得10-羟基喜树碱(4)并对其工艺条件进行了改进,氧化产率由60.2%提高到86.1%,光反应产率由30.6%提高到49.8%;再以10-羟基喜树碱(4)为原料,经乙酰化、Minisci自由基反应、水解反应,最终得到20(S)-7-对氟苯甲酰基-10-羟基喜树碱(1),并用IR、1 H NMR和MS进行了结构表征。用SRB法对1进行了体外抗肿瘤活性实验,显示1对人白血病(HL-60)、人胃癌细胞(BCG-823)、人肝癌细胞(Bel-7402)和人鼻咽癌细胞(KB)均有抑制作用。  相似文献   

16.
Ethylene diamine polyesteramide (Ed‐PEA) was synthesized from N, N‐bis (2‐hydroxy ethyl) linseed oil fattyamide and ethylene diamine tetra acetic acid through condensation polymerization. It was further treated with toluylene 2,4‐diisocyanate (TDI) in different weight percentage to obtain urethane‐modified polyesteramide (Ed‐UPEA). The structural elucidation of Ed‐PEA and Ed‐UPEA were carried out by FTIR, 1H‐NMR, and 13C‐NMR spectroscopic techniques. Thermal studies of these resins were carried by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The coatings of urethane‐modified polyesteramide were prepared on mild steel strips and their anticorrosive behavior of in acid, alkali, water, and xylene were investigated. Thermal stability performance suggests that the system could be safely used upto 200°C. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009  相似文献   

17.
Golgi protein 73 (GP73), which is up-regulated in hepatocellular carcinoma (HCC), has recently been identified as a novel serum marker for HCC diagnosis. Several reports also noted the increased levels of GP73 expression in chronic liver disease in patients with acute hepatitis of various etiologies, chronic Hepatitis C virus (HCV) infection and alcoholic liver disease. The molecular mechanisms of GP73 expression in HCV related liver disease still need to be determined. In this study, we aimed to evaluate the effect of HCV infection on GP73 expression. GP73 was highly expressed in Huh7, Hep3B, 293T and HUVEC cells, and was low-expressed in HepG2 cells. HCV infection led to down-regulation of GP73 in Huh7 and HepG2/CD81 cells at the early stage of infection. CXCL10 decreased GP73 expression in Huh7 and HepG2 cells. Up-regulation of GP73 was noted in hepatocytes with cytopathic effect at advanced stage of HCV infection, and further research is needed to determine the unknown factors affecting GP73 expression. In conclusion, our study provided additional evidence for the roles of GP73 in liver disease.  相似文献   

18.
Polyalkylthiophenes are applied in the form of thin films as active layers in organic devices. The main properties defined in the synthetic procedure that can affect the film formation are the molar mass and regioregularity degree (the content of head-to-tail, HT, linkages). These properties can be varied, at principle, by changing the conditions of the oxidative polymerization process. In this work, we evaluate the effect of oxidant addition rate, temperature and time-dependence of poly-(3-hexylthiophene), P3HT, oxidative polymerization in molar mass and regioregularity degree, besides other polymer properties such as absorption and emission of visible light. The results show that the polymer started to grow during the oxidant addition and already presents a relatively high molar mass (ca. 10,000 g/mol) just after the addition stopped. Polymerization temperature is more significant in molar mass variations than the time expended for the polymerization reaction, with values of Mw ranging from 15,000 to 70,000 g/mol in the conditions tested. The HT contents were all above 70 %, with higher variations in the two first hours of polymerization reaction and are mainly defined during the oxidant addition, which leads to higher HT contents and narrower molar mass distributions using slower additions. The solvent extraction reveals that the HT content is directly related to the polymer chains extension, being possible to improve both regioregularity degree and molar mass of P3HT.  相似文献   

19.
This work aimed at the synthesis of novel type of targetable polymeric conjugates with a sugar moiety (galactose) with potential application for liver-specific drug delivery. Simple and effective synthesis of poly(dl-lactide-co-glycolide)-galactose conjugate and poly(dl-lactide-co-glycolide)-co-poly(ethylene glycol)-10%-Triblock-galactose conjugate by esterification of the end carboxyl groups has been reported. Spherical hydrophilic nanoparticles with elevated galactose content on the surface were prepared from these polymeric conjugates, and their physical properties were determined by DLS, SEM, XPS and DSC.  相似文献   

20.
Blends based on different ratios of plasticized starch (PLST) and poly(vinyl alcohol) (PVA) were prepared in the form of thin films by casting solutions. The effect of gamma-irradiation on thermal, mechanical and morphological properties was investigated. The results of thermogravimetric analysis (TGA), in terms of weight loss and rate of reaction, indicated that the thermal stability of PLST/PVA blends is higher than pure PLST. The differential scanning calorimetry (DSC) scans do not show the glass transition temperature (Tg) of PVA or PLST, but instead a new single glass transition, indicating the occurrence of compatibility. The mechanical testing of PLST/PVA blends showed that tensile strength and elongation at break were increased by increasing the ratio of PVA. At any ratio of PLST/PVA, the tensile strength and elongation at break was found to increase with increasing irradiation dose. As an application in the field of prolonging food preservation lifetime, solutions of gamma irradiated PLST/PVA blends in the presence of chitosan, as an antimicrobial material, were applied to Mango fruits by surface coating. The results showed that this technique would provide suitable materials for food preservation that withstanding the temperature and stresses.  相似文献   

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