Effects of caffeine on lipoprotein lipase gene expression during the adipocyte differentiation process

In this study, the effects of caffeine on lipoprotein lipase (LPL) gene expression were investigated in the 3T3-F442A preadipocyte cell line during the adipocyte differentiation process by determining LPL enzymatic activity and its messenger RNA (mRNA) level. The results demonstrate that caffeine acts on the gene expression of LPL, an early marker of adipocyte differentiation. It has a biphasic action: it increases gene expression in terms of mRNA when it is added to preadipocytes during the early stage of differentiation, but this is accompanied by a reduction of enzymatic activity. On the other hand, when caffeine is added for long periods during differentiation and/or when it is added to mature adipocytes, it induces marked inhibition of mRNA levels, correlated with a marked reduction of secreted enzymatic activity. The inhibitory effect of caffeine on LPL mRNA level can be reproduced by theophylline, a phosphodiesterase inhibitor, and by dibutyryl cyclic AMP, a non-metabolizable analog of cyclic AMP. However, the effect of caffeine and theophylline lasts longer than that of cyclic AMP, suggesting that a mechanism other than inhibition of cyclic AMP hydrolysis may be involved in the action of caffeine.     

Ruins revisited: modernist conceptions of heritage

The perception westerners have of ruins underwent drastic transformations in the second half of the twentieth century. The realities of World War Two and the growing number of environmental problems made everyone realise that a ruin can be more than some enchanting reminder of distant cultures. Ruins stopped being objects of desire, precious anachronisms for adventurers to appropriate. This paper surveys emerging sensibilities towards ruins in literature, arts, archaeology and architecture. It presents a new vision, quite opposite to, but as powerful as the Beaux-Arts perspective.     

Evaporation kinetics of volatile liquids and release kinetics of water from a smectite clay: Comparison between experiments and finite element calculations

Numerical calculations of the evaporation kinetics of bulk volatile liquids and of water from smectite clay granules are compared with experimental results. The weight loss of the volatiles is analyzed by thermogravimetry and differential calorimetry. Under the thermodynamic conditions of the experiments, finite element calculations are in good agreement with the experimental data, and an approximate semi-analytical model is developed in order to explain the dependence of the rate of evaporation on the temperature, the chemical species and the carrier gas flow rate. The initial rate of evaporation of water from the clay granule is close to that for bulk water. Its decrease with time is determined mainly by changes in the gas/condensed phase partition given by the equilibrium desorption isotherm, with little limitations due to internal diffusion effects for the present experimental conditions. Its temperature dependence could also be approximately described by an Arrhenius-type equation derived from the semi-analytical model. Further analysis of the experimental measurements reveals steps in the heat of vaporization of water as a function of water concentration, that could be related to the equilibrium desorption isotherm.     

Finite element model updating and structural damage identification using OMAX data

The main limitations in the finite element (FE) model updating technique lie in the ability of the FE model to represent the true behavior of the structure (modelling problem), and in the ability to identify enough modal parameters with sufficient accuracy, especially for large structures that are tested in operational conditions (identification problem). In this paper, the identification problem is solved with an OMAX approach, where an artificial force is used in operational conditions and a structural model is identified that takes both the forced and the ambient excitation into account. From an extensive case study on a real three-span bridge, it is observed that, while updating the FE model using the experimental output-only data yields a good fit, discrepancies show up when the more extensive set of OMAX data is used for validation, or even for updating. It can be concluded that an OMAX approach not only increases the well-posedness of the updating problem, it also allows to detect potential inaccuracies in the FE model.     

AB SCIEX TripleTOF 5600在蛋白质组学研究中的应用

AB SCIEX公司最新发布全新的高分辨液相色谱质谱联用系统——TripleTOF5600是在享有盛名的API 5500三重四极杆系统和QSTAR Elite(QqTOF)系统这两个技术平台的基础上开发出来的。TripleTOF 5600高分辨液相色谱质谱联用系统能够对复杂的蛋白质组学样品进行高通量分析,并能同时提供高质量的定性和定量结果。为评估这款仪器的性能,设计基于纳升液相色谱和TripleTOF 5600联用系统的一系列实验。首先,应用这一拥有高分辨率、高灵敏度和高质量准确度的系统对酵母细胞裂解物的胰酶消化产物进行分析。实验中采用每秒最多采集50幅串联质谱谱图的信息相关采集模式,单次LC-MS/MS实验就鉴定10179条独特肽段和1174种蛋白(at 1%global false discoveryrate)。而实际达到平均每秒34幅串联谱图的采集速度是在单次实验获得如此优异的鉴定结果的决定性因素。此外,也对一组含有5种已知蛋白以及部分重同位素标记肽段的样品进行分析,以检验TripleTOF 5600的定量能力。实验中这5种蛋白质都获得很高的序列覆盖率,其中进样量仅有100amol的Peroxiredoxin 1蛋白的序列覆盖率也高达53%。而测试中得到肽段的平均质量偏差仅为1.7 ppm,展示TripleTOF 5600的高质量准确度和稳定性。此外还获得高度准确的定量结果,充分证明TripleTOF 5600能够提供三重四极杆系统级别的定量结果。     

制革生态学(续四)

3 .2　Dyeing3.2 .1　DyesandpigmentsBASFsuppliesarangeofpowderandliquiddyesundertheLuganil andLurazol trademarksfordrumdyeingofleather.ThemajorityoftheLuganil andLurazol dyesareanionicazodyesormetalcomplexdyes.Certainspecialproductsroundofftherange .Lura zol BlackPLiquidisametal freeblackpigmentinaqueousdispersion ,whichcanbeappliedincon junctionwithdyes.LeatherBlackVMLiquidisacationicdye.TheLuganil andLurazol rangescontainalargenumberofchromaticdyes,andmanydiffer entshadesofblackandbro…     

Automated DNA preparation from maize tissues and food samples suitable for real-time PCR detection of native genes

There is an increasing need for high-throughput analyses of plants and food samples for the presence of specific DNA sequences, e.g. transgenic contaminations. We developed and optimized conditions for the automated isolation of DNA from several maize tissues and various edibles containing maize using the MagNA Pure LC system (Roche Applied Science). Our results show that the system provided is capable of isolating DNA from any tested source. Quantification of an endogenous gene by LightCycler real-time PCR revealed that the DNA is suitable in quality and quantity for multiple PCR analyses.     

Anbindungsverhalten organischer Monomere auf Eisenoberflächen und Korrosion der durch die Anbindung chemisch modifizierten Oberflächen

Binding behaviour of organic monomers on iron surfaces and corrosion of the resultant chemically modified surfaces In this study a new concept is discussed, to anchor polymers onto metal surfaces by primary chemical bonds. Organic molecules with two functional groups are positioned between polymer and substrate, which should be bonded to reactive centers of the metal surface by one functional group and to the polymer by conventional C-C bonds. As a first in this direction, the reaction between simple aliphatic mercaptanes and iron surfaces has been studied in detail. Surface analytical investigations have proven, that mercaptane molecules can be bonded to metallic clean iron surfaces by Fe-S-R bonds. The reaction itself has to be performed under well controlled electro-chemical conditions. The stability of the bonds is quite large as well in air as in many different electrolytes. The stability is limited by a prolonged oxygen reduction at large cathodic overpotentials. Probably, the mercaptane molecules are chemically oxidised by the H₂O₂ formed during the reduction of oxygen and the resulting sulfonic acid desorbs from the electrode surface.     

制革生态学(续六)

4 Finishing The purpose of finishing leather is to improve its serviceability by protecting it from damage by water, soil and mechanical action. Finishing modifies the shade, gloss and handle of the leather, improves its physical properties such as its lightfasthess and rubfastness, and hides any defects and