Purification and characterization of parvalbumins from silver carp (Hypophthalmichthy molitrix)

BACKGROUND: As the largest producer and consumer of freshwater fish in the world, many people suffer from allergy for consuming freshwater fish in China. However, the allergen profiles of freshwater fish are rarely known. RESULTS: Parvalbumins (PVs) from the white muscle of silver carp (Hypophthalmichthy molitrix) were purified by ammonium sulfate fractionation and column chromatography including DEAE‐Sepharose and Superdex 75. Three PV isoforms—PV‐I, PV‐II, and PV‐III—were obtained and their molecular masses as estimated by tricine–sodium dodecyl sulfate–polyacrylamide gel electrophoresis were 12, 11, and 14 kDa, respectively. All the PVs could be detected by anti‐frog PV monoclonal antibody. PV‐I and PV‐II were quite possibly glycoproteins, while PV‐III was not glycosylated, as analyzed by periodic acid–Schiff (PAS) staining. Thermal stability revealed that PV‐I and PV‐II easily formed polymers, while these proteins were stable in a pH range of 4.0–10.0. A PV gene encoding 110 amino acid residues was cloned and it revealed high identity with PVs from other species of fish. CONCLUSION: Three isotypes of PV were purified to homogeneity and one distinct PV gene was cloned in silver carp white muscle. Copyright © 2010 Society of Chemical Industry     

(De)stabilization of required and spontaneous postural dynamics with learning.

The present research examined how learning a new ankle-hip coordination influenced the preexisting postural repertoire. Standing participants learned a new ankle-hip coordination mode (relative phase of 90'). Before and after practice, postural patterns were evaluated in two different tasks. In the required task, specific ankle-hip patterns were requested (12 relative phases in multiples of 30'). In the spontaneous task, participants performed a tracking task in which no instructions about ankle-hip coordination were given. Learning induced changes in both required and spontaneous coordination dynamics. When ankle-hip patterns were required, learning led to improvement and homogenization in performance over the entire postural repertoire. When ankle-hip patterns emerged spontaneously, in-phase and antiphase preexisting patterns destabilized and changed toward the learned pattern of 90'. These findings demonstrate that learning a new coordination pattern can induce modifications of patterns that have not been practiced. The results also suggest that the consequences of learning do not generalize across different types of tasks, even when similar coordination modes are involved. We discuss implications of these findings for the generality of learning mechanisms. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

格林尼亚反应合成全氘代-α-苯乙醇

以重水 (D2 O)及电石 (CaC2 )为原料 ,先制得氘代乙醛 (CD3CDO) ;氘代苯则与溴和金属镁反应生成氘代苯基溴化镁 (C6D5MgBr)。CD3CDO再与C6D5MgBr进行格林尼亚反应 ,并用酸性重水溶液水解 ,最终制得氘代率xD≈ 99%的全氘代 α 苯乙醇 (C6D5—CDODCD3) ,产率 71.2 % (以氘代溴苯计 )。作者介绍了以D2 O、CaC2 及C6D6为原料制备C6D5—CDODCD3 的合成工艺及采用内标相对摩尔校正因子氢核磁共振波谱 (1HNMR)技术表征产物氘代率的方法     

The effect of elevated inlet air temperature and relative humidity on cogeneration system

The effect of elevated inlet air temperature and relative humidity on a gas turbine (GT) cogeneration system performance was investigated. The analysis was carried out on a GT of a capacity 171 MW at ISO condition, which is integrated with a dual pressure heat recovery steam generator (HRSG), the cogeneration system had been tested under Kuwait summer climate conditions. A computational model was developed and solved using engineering equation solver professional package to investigate the performance of a dual pressure GT‐HRSG system. The suggested HRSG is capable of producing high‐pressure superheated steam at 150 bar and 510°C to operate a power generation steam turbine cycle, and a medium pressure saturated steam at 15 bar to run a thermal vapor compression (TVC) desalination system. In this research, the influence of elevated inlet air temperature and relative humidity on the energy assessment of the suggested cogeneration system was thoroughly investigated. Results indicated that operating GT under elevated values of inlet air temperatures is characterized by low values of net power and thermal efficiency. At elevated inlet air temperatures, increasing relative humidity has a small positive impact on GT cycle net power and thermal efficiency. Integrating the GT with HRSG to generate steam for power generation and process heat tends to increase energy utilization factor of the system at elevated inlet air temperatures. Increasing inlet air temperature plays a negative impact on power to heat ratio (PHR), while relative humidity has no effect on PHR. Copyright © 2009 John Wiley & Sons, Ltd.     

Influence of hydroxyvalerate composition of polyhydroxy butyrate valerate (PHBV) copolymer on bone cell viability and in vitro degradation

The objective of this study was to elucidate the role of hydroxyvalerate (HV) composition in polyhydroxy butyrate valerate (PHBV) copolymer film on the degradation of copolymer and osteoblastic cell activity. Degradation was studied by monitoring time‐dependent changes in mass and chemical composition of the macroporous films. The mass loss of PHBV film upon 19 weeks of exposure to pH 7.4 phosphate buffer medium was found to range from 2.8% to 9.2% with a strong dependence on the original composition of the copolyester film and morphology. Tapping mode atomic force microscopy (TMAFM) was used to examine the roughness change of polyester films due to exposure to buffer medium. Chemical analysis of the degraded film was carried out using NMR to aid in the interpretation of the mass loss and TMAFM data. The NMR results showed a significant decrease in the mol % of HV content in the degraded PHBV film. Additionally, we established that UMR‐106 cell proliferation on macroporous PHBV matrix is minimally enhanced by the HV content of PHBV copolymer. Information provided by this study can be used in the selection of appropriate PHBV copolymer for clinical use where the biopolymer needs to remain physically intact and chemically unchanged during the intended period of biomedical application. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

大学章程之制定主体相关问题探析

大学章程制定权实质是大学自治权的核心,在法治原则下,其来源于法律的授予。法律授予制定权的对象为制定主体,制定主体中真正起作用的是行使审议和表决通过权的决策主体,行使其他权利的则为影响主体。域内外各地区有关大学章程制定主体的实践表明,制定主体一般为大学各方利益主体的联合大会。     

The effects of post annealing on the mechanical properties, microstructure and texture evolutions of pure copper deformed by twist extrusion process

X-ray diffraction peak broadening analysis showed that performing a proper heat treatment between the twist extrusion passes of commercially pure copper decreased the coherent domain size and increased the microstrain. Moreover, SEM micrographs illustrated that annealed material contained new formed grains that could not grow due to lack of sufficient time. Under such circumstances, the ultimate strength was elevated about 45 MPa. The deformed material showed texture of simple shear deformation, changing by applying the post annealing.     

The Effect of Ketone Defects on the Charge Transport and Charge Recombination in Polyfluorenes

The effect of on‐chain ketone defects on the charge transport of the polyfluorene derivative poly(9,9‐dioctylfluorene) (PFO) is investigated. Using MoO₃ as ohmic hole contact, the hole transport in a pristine PFO diode is observed to be limited by space‐charge, whereas fluorenone contaminated PFO (PFO‐F) is shown to be trap limited by the occurrence of an exponential trap distribution with a trap depth of 0.18 eV. The electron transport in PFO is also observed to be trap limited, but in order to describe the electron transport of PFO‐F, an additional trap level with a depth of 0.46 eV must be introduced. The obtained energy levels of the fluorenone trapping sites are in close agreement with cyclic voltammetry (CV) measurements reported in literature. As a result, the fluorenone defects are shown to simultaneously act as hole‐ and electron trap. Moreover, through ideality factor measurements, the green emission associated with these defects is observed to originate from trap‐assisted recombination.     

The Role of Lattice Matching Techniques in the Characterization of Polymorphic Forms

An inspection of the recent literature reveals that polymorphism is a frequently encountered phenomenon. The recognition of polymorphic forms plays a vital role in the materials sciences because such structures are characterized by different crystal packing and accordingly have different physical properties. In the pharmaceutical industry, recognition of polymorphic forms can be critical for, in certain cases, a polymorphic form of a drug may be an ineffective therapeutic agent due to its unfavorable physical properties. A check of the recent literature has revealed that in some cases new polymorphic forms are not recognized. In other instances, a supposedly new polymeric form is actually the result of an incorrect structure determination. Fortunately, lattice-matching techniques, which have proved invaluable in the identification and characterization of crystal structures, represent a powerful tool for analyzing polymorphic forms. These lattice-matching methods are based on either of two strategies: (a) the reduced cell strategy–the matching of reduced cells of the respective lattices or (b) the matrix strategy–the determination of a matrix or matrices relating the two lattices coupled with an analysis of the matrix elements. Herein, these techniques are applied to three typical cases–(a) the identification of a new polymorphic form, (b) the demonstration that a substance may not be a new polymorphic form due to missed symmetry, and (c) the evaluation of pseudo polymorphism because of a missed lattice. To identify new polymorphic forms and to prevent errors, it is recommended that these lattice matching techniques become an integral part of the editorial review process of crystallography journals.     

Scanning transmission ion microscopy of polycarbonate nanocapillaries

Polycarbonate membranes containing statistically scattered heavy ion track nanocapillaries have been studied by scanning transmission ion microscopy (STIM) method. The geometry of the samples was characterized by pore diameters of about 172 nm and by 30 μm membrane thickness. The porosity has to be relatively low in order to avoid too many overlapping capillaries. The transparency of the sample is reduced by changing its tilt angle to the beam. While the acceptance angle for transmission of a single capillary is below 0.3°, the STIM results have showed that the angular spread was about 1° full width at half maximum (FWHM). This indicates that the capillaries are not perfectly parallel, i.e. the capillary directions have a finite angular spread.Our results are important for the recent use of these types of insulator membranes in ion guiding studies, and the related potential applications.