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31.
Purification and Characterization of Pepsin-Solubilized Collagen from Skin of Sea Cucumber Holothuria parva 总被引:1,自引:0,他引:1
Nasim Adibzadeh Saeed Aminzadeh Shahla Jamili Ali Asghar Karkhane Naser Farrokhi 《Applied biochemistry and biotechnology》2014,173(1):143-154
Pepsin-solubilized collagen (PSC) was extracted from the skin of sea cucumber Holothuria parva and was fractionally characterized. The PSC from H. parva skin consisted of three α1 chains (α1)3, in contrast to calf skin collagen type I with two α1 and one α2 chains (α1)2α2 with approximately 130 kDa each. The maximum transition (Tm) and denaturation temperature (Td) of PSC were determined to be 46.94 and 32.5 °C, respectively. The amino acid composition analysis revealed that glycine, proline, alanine, and hydroxyproline were the abundant amino acids available in extracted PSC. The results showed that the isolated collagen from H. parva has some similar characteristics to previously reported collagens used in food and pharmaceutical industries. 相似文献
32.
Preparation and application of gold 2-mercaptosuccinic acid self-assembled monolayer (Au-MSA SAM) electrode for determination of iron(III) in the presence of iron(II) is described by cyclic voltammetry, electrochemical impedance spectroscopy, and Osteryoung square wave voltammetry. The square wave voltammograms showed a sharp peak around positive potentials +0.250 V that was used for construction of the calibration curve. Parameters influencing the method were optimized. A linear range calibration curve from 1.0 × 10−10 to 6.0 × 10−9 M iron(III) with a detection limit of 3.0 × 10−11 M and relative standard deviation (R.S.D.) of 6.5% for n = 8 at 1.0 × 10−9 M iron(III) was observed in the best conditions. Possible interferences from the coexisting ions were also investigated. The results demonstrated that sensor could be used for determination of iron(III) in the presence of various ions. The validity of the method and applicability of the sensor were successfully tested by determining of iron(III) in natural waters (tap and mineral waters) and in a pharmaceutical sample (Venofer® ampoule) without interference from sample matrix. The experimental data are presented and discussed from which the new sensor is characterized. 相似文献
33.
T.?HayatEmail author K.?Hutter S.?Nadeem S.?Asghar 《Zeitschrift für Angewandte Mathematik und Physik (ZAMP)》2004,55(4):626-641
The purpose of this work is to investigate the hydromagnetic oscillatory flow of a fluid
bounded by a porous plate, when the entire system rotates about an axis normal to the plate. The
fluid is assumed to be non-Newtonian (second grade), incompressible and electrically conducting.
The magnetic field is applied transversely to the direction of the flow. Such a flow model has
great significance not only of its theoretical interest, but also for applications to geophysics
and engineering. The resulting initial value problem has been solved analytically for steady and
unsteady cases. The analysis of the obtained results showed that the flow field is appreciably
influenced by the material parameter of the second grade fluid, the applied magnetic field, the
imposed frequency, rotation and suction and blowing parameters. It is observed in a second grade
fluid that a steady asymptotic hydromagnetic solution exists for blowing and resonance which is
different from the hydrodynamic situation. 相似文献
34.
以对硝基苯酚(4-NP)为对象,采用非印迹聚合物(NIP)库筛选法选出乙烯基咪唑为最佳功能单体,通过实验选出乙腈为最合适的聚合溶剂、三甲氧基丙基三甲基丙烯酸酯(TRIM)为交联剂制备分子印迹聚合物。对固相萃取进行了优化,用pH=2.5的磷酸盐缓冲溶液上样、体积比为45∶55的乙腈和磷酸盐缓冲溶液淋洗、甲醇洗脱条件下,聚合物具有最佳印迹效果。4-NP分子印迹聚合物的表观吸附量达到5.8 mg/g。该印迹聚合物对4-NP及其结构类似物苯酚和对氯苯酚的萃取回收率分别为96.0%、78.8%和77.8%,表明具有较高的选择性,还成功地用于自来水样品中4-NP的固相萃取,回收率达到93.1%。由此可得该方法快速、有效,可用于分子印迹聚合物优化制备。 相似文献
35.
Exact analytical solutions for a class of unsteady unidirectional flows of an incompressible second-order fluid are constructed. The flows are generated impulsively from rest by motion of a plate or two plates or by sudden application of a pressure gradient. Expressions for velocity, flux and skin friction are obtained for both large and small times. It is found that large and small times solutions are dependent on the coefficient of viscoelasticity. The solutions corresponding to Newtonian fluids can be easily obtained from those for fluids of second order by letting the viscoelastic parameter to be zero. 相似文献
36.
37.
38.
Summary Love wave travelling in a layer of uniform thickness overlying a half-space is assumed to be incident on two parallel but
staggered perfectly weak half-planes lying in the upper layer. The diffracted field is calculated using the modified Wiener-Hopf
technique and contour integration method. The diffracted waves satisfy the dispersion relations appropriate to different regions
formed by the perfectly weak half-planes.
To the memory of M. H. Kazi 相似文献
39.
Summary The problem of calculating the field within imperfectly conducting parallel-plates is considered. The solution in closed form is obtained using the Wiener-Hopf technique. The comparison has been made with that of perfectly conducting parallel plates waveguide.
Zusammenfassung Das Problem der Feldberechnung in unvollständig leitenden parallelen Platten wird betrachtet. Die Lösung in geschlossener Form wird mittels der Wiener-Hopf Technik gefunden, sowie ein Vergleich mit der Lösung für vollständig leitende Parallelplatten-Wellenleiter durchgeführt.相似文献
40.
Ali Asghar Rastegari Abdol-Khalegh Bordbar Vajihe Mehnati-Najafabadi 《Cellulose (London, England)》2010,17(6):1213-1225
The present study evaluates the binding of cetylpyridinium chloride (CPC) with cellulase in various experimental conditions
using potentiometric, fluorescence spectroscopy and turbidimetric techniques. The analysis of binding curves revealed the
existence of two sets of binding sets for CPC. The binding parameters were estimated and interpreted in terms of structural
viewpoints of cellulase. The observation of turbidity suggests that CPC molecules individually nucleate around cellulase/CMC
complex to form micelle-like structures. Fluorescence spectroscopy analysis of cellulase/CMC-surfactant system showed that
these complexes could be compact to elucidate the mechanism of binding cellulase/CMC complex to CPC. The differential response
of the enzyme/CMC to surfactant, indicates that the interaction on the complex surface is strongly ionic and hydrophobic(cooperative)
in nature. A sequencing analysis was also conducted on β-1, 4-endoglucanase from A. niger (EglA) and others from family 12 in order to examine the nature of interaction involved in binding process and structure
of carbohydrate-protein complexes. The results suggest that the conserved residues are located in a more hydrophobic microenvironment
and apolar area energy is more than polar within enzyme structure. 相似文献