Proteomic analysis of responses of a new probiotic bacterium Lactobacillus casei Zhang to low acid stress

Tolerance to acid is an important feature for probiotic bacteria during transition through the gastrointestinal tract. Proteomics analysis of a new probiotic bacterium, Lactobacillus casei Zhang, was performed upon 30-min exposure to low acid stress (pH 2.5 vs. pH 6.4) using two-dimensional electrophoresis. Out of 33 protein spots that showed changes of expression between the two pHs, 22 showed 1.5-fold higher expression at pH 2.5 than at pH 6.4, whereas five spots had expression decreased by 1.5-fold at pH 2.5. There were also six protein spots that were exclusively present on different pH maps. Further analysis showed that eight of the enhanced proteins, NagA, NagB, PGM, GlmM, LacC, TDP, GALM and PtsI, were involved in carbohydrate catabolism. Moreover, quantitative RT-PCR showed that the mRNA expression levels of dnaK, nagB, galm, estC, tuf and luxS were consistent with changes in protein expression. We postulate that there might be some relationship between differentially expressed proteins and acid tolerance in L. casei Zhang.     

绍兴纺织产业集群物流管理研究

纺织产业在绍兴市经济中占有非常重要的地位,其经济总量约占全市经济总量的半壁江山,位于绍兴县的中国轻纺城是亚洲最大的纺织品集散中心,纺织产业集群已经形成,但纺织产业发展所依托的物流服务却存在着诸如集群物流服务供应链不完整等问题。剖析了绍兴纺织产业集群物流特征及其发展中存在的一些问题,提出了完善绍兴纺织产业集群物流的对策。     

Issues in the Reconstruction of Gene Order Evolution

As genomes evolve over hundreds of millions years, the chromosomes become rearranged, with segments of some chromosomes inverted, while other chromosomes reciprocally exchange chunks from their ends. These rearrangements lead to the scrambling of the elements of one genome with respect to another descended from a common ancestor. Multidisciplinary work undertakes to mathematically model these processes and to develop statistical analyses and mathematical algorithms to understand the scrambling in the chromo...     

Mixed protein-templated luminescent metal clusters (Au and Pt) for H2O2 sensing

A simple and cost-effective method to synthesize the luminescent noble metal clusters (Au and Pt) in chicken egg white aqueous solution at room temperature is reported. The red-emitting Au cluster is used as fluorescent probe for sensitive detection of H₂O₂.     

粘性指进现象分数维与宏观参量的关系

计入表面张力效应,在随机网格上利用与传统方法不同的改型DLA生长模型,通过调节模型参数,模拟了被驱替液和驱替液之间粘度比V_R在1～10000范围内变化时Hel-Shaw盒中粘性指进现象的演化特征,计算了相应的分形维数D,得到与实验相符的结果。研究发现D和V_R之间满足如下关系式D=2.0384-0.0384V_R^1/3,而驱扫效率E_S和V_R的对数成正比,E_S=1-0.1795log(V_R).这说明当其它参数不变时,V_R愈大,相应的分形维数D就愈小,驱扫效率E_S也就愈低。通过分形维数D这一描述系统复杂性的抽象概念和驱替过程宏观参量V_R和E_S的联系,可以把分形维数D作为评价驱油效率的一个指标,把增加D值、降低V_R作为提高驱油效率及合理开发油田、提高采收率的一个手段。     

From Molecular Clusters to Metal Nanoparticles

Different methods to prepare supported metal nanoparticles of uniform size are discussed. (i) Supported ruthenium particles were generated from Ru and Ru-Fe bimetallic molecular metal carbonyl cluster precursors (MCC). (ii) Gold nanoparticle formation in the supercage of Y zeolite was studied on Au/NaY, Au/HY and Au-Fe/HY system. (iii) Palladium nanoparticles were grown in liquid phase then deposited on an SiO₂ support or they were grown on the support surface in a solid-liquid interfacial layer. The particle size control was more efficient in the latter two cases than in the preparation starting from MCC.     

The thermoelectric transport through carbon chains

We investigate the thermoelectric transport properties of carbon atomic clusters connected with two Al electrodes using the first-principles density functional analysis combined with the non-equilibrium Green’s function approach. We find that due to the quantum interference the thermopower S changes sign for even-odd number of carbon atoms. The thermal conductance κ is always positive with a similar oscillation between even- and odd-number of carbon atoms. Due to the orthogonalization of the wave functions of the atomic electrodes and the carbon clusters, the electric conductance G is very small for certain range of chemical potentials. Giant thermopower is found in this region. Our results show that the thermopower and thermal conductance are sensitively related to the distance d between the carbon atomic cluster and the Al electrodes. Oscillatory behaviors of S and κ are found as d is varied.     

Targeting optimum resource allocation using reverse problem formulations and property clustering techniques

Decoupling the constitutive equations from the balance and constraint equations allows for reformulating a conventional forward problem into two reverse problems. The first reverse problem is the reverse of a simulation problem, where the process model is solved in terms of the constitutive (synthesis/design) variables instead of the process variables, thus providing the synthesis/design targets. The second reverse problem (reverse property prediction) solves the constitutive equations to identify unit operations, operating conditions and/or products by matching the synthesis/design targets. Visualization of the problem is achieved by employing recently developed property clustering techniques, which allows a high-dimensional problem to be visualized in two or three dimensions. The clusters by definition satisfy intra-stream and inter-stream conservation through linear “mixing” rules, which allows for the development of consistent additive rules along with their ternary representation.     

Germanium-antimony-selenium-tellurium thin films: Clusters formation by laser ablation and comparison with clusters from mixtures of elements

Quaternary germanium-antimony-selenium-tellurium (Ge-Sb-Se-Te) thin films deposited from Ge_19.4Sb_16.7Se_63.9−xTe_x (x = 5, 10, 15, and 20) glass-ceramics targets by radio frequency magnetron sputtering were studied using laser ablation quadrupole ion trap time of flight mass spectrometry. Binary, ternary, and quaternary Ge_aSb_bSe_cTe_d clusters were formed and their stoichiometry was determined. By comparison of the clusters obtained from quaternary Ge-Sb-Se-Te thin films and those from ternary Ge-Sb-Te materials, we found that Ge-Te species are not detected from the quaternary system. Furthermore, Ge-Se and Se-Te species are missing in mass spectra generated from Ge-Sb-Se-Te thin films. From the Ge-Sb-Se-Te thin films, 16 clusters were detected while ternary Ge-Sb-Se glasses yielded 26 species. This might be considered as a signal of higher stability of Ge-Sb-Se-Te thin films which is increasing with a higher content of Te. The missing (Se₂⁺, Ge_aSb⁺ (a = 1–4), and GeSe_c⁺ (c = 1, 2)) and new (Ge⁺ and Sb_bTe⁺ (b = 1–3)) clusters may indicate that some of the structural features of the films (Ge₂Se_6/2 and Se₂Sb-SbSe₂) were replaced by (GeSe_4−xTe_x and SbSe_3−xTe_x) ones. In addition, when comparing the stoichiometry of clusters formed from Ge-Sb-Se-Te thin films with those from the mixtures of the elements, only Sb₃⁺ and SbSe⁺ were observed in both cases. The knowledge gained concerning clusters stoichiometry contributes to the elucidation of the processes proceeding during plasma formation used for the chalcogenide thin films deposition.