Electrophoretic and zymographic characterization of proteins isolated by various extraction methods from ejaculated and capacitated boar sperms

The presented work focuses on electrophoretic and zymographic characterization of boar sperm proteins isolated by various extraction methods and on comparison of the protein profiles obtained from ejaculated and in vitro capacitated spermatozoa. Sperm proteins of ejaculated and in vitro capacitated boar sperms were isolated with the following agents: 1% v/v Triton X‐100, 1% v/v Triton X‐114, 2% v/v acetic acid, 1% m/v sodium dodecyl sulphate (SDS), 30 mM N‐octyl‐β‐D ‐glucopyranoside (OBG), rehydration buffer (RHB) for isoelectric focusing and finally by the freezing–thawing approach. The extracts were characterized in terms of 1‐DE, 2‐DE protein profiles, 1‐DE glycoprotein staining and proteinase and hyaluronidase substrate zymographic profiles. The results have shown quantitative and qualitative differences in 1‐DE protein and glycoprotein profiles with respect to the employed isolation approach. These differences were seen even more clearly in 2‐DE protein profiles, where it was possible to distinguish the presence/absence, changes in relative abundance and pI/M_r shifts of various protein spots. Proteinase and hyaluronidase zymograms supported the prediction that various isolation protocols result in various profiles of enzymatically active molecules.     

A complementary mobile phase approach based on the peak count concept oriented to the full resolution of complex mixtures

Situations of minimal resolution are often found in liquid chromatography, when samples that contain a large number of compounds, or highly similar in terms of structure and/or polarity, are analysed. This makes full resolution with a single separation condition (e.g., mobile phase, gradient or column) unfeasible. In this work, the optimisation of the resolution of such samples in reversed-phase liquid chromatography is approached using two or more isocratic mobile phases with a complementary resolution behaviour (complementary mobile phases, CMPs). Each mobile phase is dedicated to the separation of a group of compounds. The CMPs are selected in such a way that, when the separation is considered globally, all the compounds in the sample are satisfactorily resolved. The search of optimal CMPs can be carried out through a comprehensive examination of the mobile phases in a selected domain. The computation time of this search has been reported to be substantially reduced by application of a genetic algorithm with local search (LOGA). A much simpler approach is here described, which is accessible to non-experts in programming, and offers solutions of the same quality as LOGA, with a similar computation time. The approach makes a sequential search of CMPs based on the peak count concept, which is the number of peaks exceeding a pre-established resolution threshold. The new approach is described using as test sample a mixture of 30 probe compounds, 23 of them with an ionisable character, and the pH and organic solvent contents as experimental factors.     

Physical design of positronium time of flight spectroscopy apparatus

Positronium time of flight spectroscopy(Ps-TOF)is an effective technique for porous material research.It has advantages over other techniques for analyzing the porosity and pore tortuosity of materials.This paper describes a design for Ps-TOF apparatus based on the Beijing intense slow positron beam,supplying a new material characterization technique.In order to improve the time resolution and increase the count rate of the apparatus,the detector system is optimized.For 3 eV o-Ps,the time broadening is 7.66 ns and the count rate is 3 cps after correction.     

产业集聚与新企业进入的计数模型分析

鉴于新企业对经济发展的推动作用,本文利用负二项同归模型对企业影响因素进行研究,实证研究表明出市场准入门槛、最优经济规模等影响因素外,产业集聚状况对新企业进入只有积极影响,而且产业集聚区的企业规模及产业集聚区所在地的城市化水平均对新企业活动产生影响。