Phenolic potential of Tannat, Cabernet-Sauvignon and Merlot grapes and their correspondence with wine composition

The phenolic potential of Tannat, Cabernet-Sauvignon and Merlot grapes was evaluated in 2001 and 2002 and its correspondence with the colour and composition of the respective wines was established. Three vineyards of each variety, situated in the south of Uruguay were considered. Two samples of each vineyard were taken at the moment of the harvest. Phenolic richness, extractable anthocyanins contents and total potential in anthocyanins of the grapes were estimated. Two fermentations on skins were carried out for each vineyard using 50 kg of grape in each one. The anthocyanic and total polyphenols contents of the musts were analysed every 24 h, and skins extractions were carried out in parallel in the laboratory. The duration of the maceration for each variety was decided in function of the analytical results in the grapes, musts and skins extractions. Wines were analysed 2 months after the alcoholic fermentation, determining its phenolic composition and colour. Tannat grapes presented anthocyanic and total polyphenols contents significantly higher in both years. Therefore, wines from this variety presented colour intensity and phenolic contents statistically higher than Cabernet-Sauvignon and Merlot. The correlations between the phenolic contents of the grapes, skins, musts and wines were very significant. Colour intensity and phenolic contents of the wines were highly correlated with the total polyphenols of the grapes and with anthocyanins of the grapes, skins, musts and wines. The estimate of the phenolic potential of the grapes and the extractability of the pigments allows to manage more adequately the fermentation on skins and is an interesting tool to predict the colour and the composition of the wines.     

Volatile components of selected liverworts, and cytotoxic, radical scavenging and antimicrobial activities of their crude extracts

Crude extracts of the Tahitian liverworts Mastigophora diclados and Frullania sp., the Indonesian Frullania sp., Dumortiera hirsuta and Marchantia sp., and the Japanese Porella perrottetiana were investigated chemically by using gas chromatography-mass spectrometry (GC-MS). All extracts contained various volatile sesqui- and diterpenoids and a few aromatic compounds. The Tahitian M. diclados and Frullania sp., and the Indonesian Frullania sp. exhibited cytotoxic activity against HL-60 and KB cell lines. The extracts of the Tahitian M. diclados and the Indonesian Marchantia sp. showed radical scavenging activity, whereas the crude extracts of the Tahitian M. diclados and Frullania sp., and the Indonesian Frullania and Marchantia sp. showed antimicrobial activity against Staphylococcus aureus and Bacillus subtilis.     

Contributions to the Chemistry of the Binary Compounds of the Transition Elements

Phase and structural relationships of the sulfur, selenium, and tellurium compounds of the 4d and 5d transition elements of groups IV to VII of the periodic system are discussed. Homologous elements behave very similarly with respect to the chalcogens, and this is particularly the case for niobium and tantalum, and for molybdenum and tungsten. However, zirconium, niobium, and molybdenum have a greater tendency towards formation of chalcogen-poor phases than their homologues hafnium, tantalum, and tungsten. Subchalcogenides are known only for zirconium and niobium. The number of phases and the tendency towards formation of solid solutions are considerably smaller among the tellurides than among the sulfides and selenides. The crystal structures of the telluride phases also differ from those of the sulfide and selenide phases of analogous composition. In addition, a review of the phase and structural relationships of the arsenic and antimony compounds of the 4d and 5d transition elements of groups V to VII is given.     

“治气”与“养心”：荀子身心修炼的功夫论

荀子的功夫论有两个方面：一是功夫实践所指向的理想人格;一是作为功夫实践具体方法的“治气养心之术”。就前者而言,荀子在继承孔、孟的“士”“君子”和“圣人”观念的基础上,提出了“士君子”和“大儒”的特有观念,同时明确界说了理想人格的不同层次与形态。后者作为身心修炼的过程,指“虚一而静”的“大清明”之“心”,经由“师法”的学习,透过“礼乐”的熏陶,对治自身的“气”“性”,以“得师”和“由礼”为根本环节。“心”由“得师”“隆礼”而“化性起伪”,呈现为一个由外而内的“锻造”过程。“气”指“血气”,包括自然欲望、生理本能以及心理情绪在内的身体方面。“心”是认知、判断和选择的能力,并没有道德之“善”的内容,即便是“虚一而静”的“大清明心”,本身也不以“善”为其固有内容。由于“师法”和“礼乐”都是心外的候选对象,“治气养心之术”需要面对“师”“礼”最初如何产生以及“得师”“由礼”能否必然的问题,成就理想人格也随之成为一种或然的选择和他律的结果。但即便如此,无论就个体还是大多数人的普遍实践而言,“得师”“由礼”的身心修炼更为切实可行,尤其对社会文明的建设来说,即便没有“仁义内在”的预设,也更具普遍的适用性和有效性。     

Calibration methods for microdialysis sampling in vivo: muscle and adipose tissue

Calibration methods for microdialysis sampling were studied in the muscle and adipose tissue of rats. Both the delivery method and the no-net-flux method were used to determine the extraction efficiency (EE) of acetaminophen and caffeine in both tissues. There was no concentration dependence of the EE either in vitro or in vivo for either acetaminophen or caffeine. The EEs determined by the delivery and no-net-flux methods were not different. However, the EEs of both caffeine and acetaminophen determined in vitro were significantly higher than those determined in the muscle and adipose. This indicates that mass transfer in the tissue is the rate-determining factor for the EE in vivo. The relative difference between the EE in vitro and the EE in the muscle was smaller than the difference between the EE in vitro and the EE in the adipose. In addition, the EE in the muscle decreased more than the EE in the adipose after the animal was euthanized. This indicated that exchange between the extracellular fluid and plasma is the rate-determining step in mass transport relative to microdialysis sampling. This has a more significant effect on the EE in the muscle than the EE in the adipose. Both the delivery and no-net-flux methods can be used to calibrate microdialysis probes in the muscle and adipose.     

基于无基底扣除的数据趋势累积谱峰检测算法

谱峰的检测分析在色谱技术研究中具有十分重要的作用,但在色谱数据采集、传输的过程中,不同程度的噪声干扰给谱峰检测带来了极大的困难.目前传统的谱峰检测算法普遍通过基底扣除的方式对谱峰的形态进行预定义,将谱峰分为单峰、重叠峰等多个种类.针对不同种类的谱峰采用不同的检测方法,这就导致了传统的谱峰检测算法具有高复杂度、低自动化程...     

Excited state properties of the chromophore of the asFP595 chromoprotein: 2D and 3D theoretical analyses

The ground and excited state properties (e.g., the intramolecular charge and energy transfer, and electron‐hole coherence) of the chromophore of the asFP595 chromoprotein from Anemonia sulcata in the neutral and anionic forms are theoretically studied with quantum chemistry methods. The ground‐state properties of the asFP595 in the neutral and anionic forms, such as the alternations of the bond lengths and the Mulliken charge distributions, are compared. The calculated transition energies of the asFP595 in the neutral and anionic form are consistent with the experimental results. To study the excited state properties of the asFP595 chromophore, the energies and densities of highest occupied molecular orbitals (HOMOs) and lowest unoccupied molecular orbitals (LUMOs), as well as the CI main coefficients, are compared between the two forms. The intramolecular charge and energy transfer in the neutral and anionic forms are investigated and compared with the three‐dimensional (3D) real‐space analysis methods, including the strength and orientation of the transition dipoles with transition density, and the orientation and result of the intramolecular charge transfer with charge difference density. The electron‐hole coherence and delocalization on the excitation are studied with the 2D real‐space analysis method of the transition density matrix. In all, the calculated results are remain in good agreement with the experimental data, and the theoretical analysis results supported the proposed models in the experiment. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2006     

Numerical simulation of bubble dynamics in a micro-channel under a nonuniform electric field

A numerical method is used to simulate the motion and coalescence of air bubbles in a micro-channel under a nonuniform electric field. The channel is equipped with arrays of electrodes embedded in its wall and voltages are applied on the electrodes to generate a specified electric field gradient in the longitudinal direction. In the study, the Navier-Stokes equations are solved by using the level set method handling the deformable/moving interfaces between the bubbles and the ambient liquid. Both the polarization Coulomb force and the dielectrophoresis force are considered as the force source of the Navier-Stokes equations by solving the Maxwell's equations. The flow field equations and the electric field equations are coupled and solved by using the finite element method. The electric field characteristics and the dynamic behavior of a bubble are analyzed by studying the distributions of the electric field and the force, the deformation and the moving velocity of the air bubble. The result suggests that the model of dispersed drops suspended in the immiscible dielectric liquid and driven by a nonuniform electric field is an effective method for the transportation and coalescence of micro-drops.     

纳米粒子的精准组装

纳米材料由于其独特的光、电、磁、力学等性质,成为了构建功能材料与器件的理想基元。实现纳米粒子的精确组装,是探究粒子之间的耦合聚集性质和制备宏观功能器件的基础。但是由于纳米粒子的小尺寸以及在溶液中运动的随机性与复杂性,精准控制纳米粒子组装体的形貌以及在空间中的相对位置仍存在巨大挑战。为了将纳米粒子组装成理想的有序结构,许多控制粒子组装的策略与方法得到发展。本文首先概述了纳米粒子自组装的控制方法与典型形貌,着重分析了影响粒子精准排布的因素与控制方法,并对纳米粒子及其组装体的光学性质与器件应用的最新研究进展进行了讨论,最后对目前纳米粒子精准组装所面临的挑战以及未来发展的方向进行了展望。     

A Hirshfeld-I interpretation of the charge distribution, dipole and quadrupole moments of the halogenated acetylenes FCCH, ClCCH, BrCCH, and ICCH

We report the dipole and quadrupole moments of the halogenated acetylenes calculated using large basis sets and the SCF, DFT(B3LYP), and CCSD methods, and we analyze the charge density using the Hirshfeld and Hirshfeld-I techniques. The atomic charges, dipoles, and quadrupoles resulting from the Hirshfeld-I analysis are used to interpret the unusually small molecular dipole moments in the sequence as well as the molecular quadrupole moments. The very small dipoles obtain for two reasons. First, the dipole moment associated with the σ and π electron densities is comparable in magnitude and opposite in direction. Second, the charge and induced dipole contributions for ClCCH, BrCCH, and ICCH have opposite signs further reducing the molecular dipoles. The molecular quadrupole moments are the sum of a charge, atomic dipole, and in situ quadrupole terms, and are dominated by the atomic dipoles and in situ quadrupoles with the charge contributions playing an unexpectedly minor role.     

Nonisotopic single-strand conformation polymorphism analysis of sequence variability in ribosomal DNA expansion segments within the genus Trichinella (Nematoda: Adenophorea)

A nonisotopic single-strand conformation polymorphism (SSCP) approach was employed to 'fingerprint' sequence variability in the expansion segment 5 (ES5) of domain IV and the D3 domain of nuclear ribosomal DNA within and/or among isolates and individual muscle (first-stage) larvae representing all currently recognized species/genotypes of Trichinella. In addition, phylogenetic analyses of the D3 sequence data set, employing three different tree-building algorithms, examined the relationships among all of them. These analyses showed strong support that the encapsulated species T. spiralis and T. nelsoni formed a group to the exclusion of the other encapsulated species T. britovi and its related genotypes Trichinella T8 and T9 and T. murrelli, and T. nativa and Trichinella T6, and strong support that T. nativa and Trichinella T6 grouped together. Also, these eight encapsulated members grouped to the exclusion of the nonencapsulated species T. papuae and T. zimbabwensis and the three representatives of T. pseudospiralis investigated. The findings showed that nonencapsulated species constitute a complex group which is distinct from the encapsulated species and supported the current hypothesis that encapsulated Trichinella group external to the nonencapsulated forms, in accordance with independent biological and biochemical data sets.     

STUDY ON THE INTERACTION BETWEEN POLYVINYLPYRROLIDONE AND PLATINUM METALS DURING THE FORMATION OF THE COLLOIDAL METAL NANOPARTICLES

Several PVP-stabilized colloidal platinum metals nanoparticles have been synthesized and characterized by FTIR and TEM.Comparing with the pure PVP,carbonyl groups of PVP in the mixture of PVP and the metal precursors or in the PVP-stabilized metal nanoparticles have obvious peak shifts in FTIR spectra.The peak shifts reveal the interaction between PVP and the metal species.The interaction between PVP and metal precursors has effect on the formation of the colloidal metal nanoparticles.Strength of the int...     

Finite Element Analysis and Structure Optimization for Improving the Fatigue Life of Rubber Mounts

The fatigue crack problem of a rubber mount on the crankshaft of a wheel in an automobile was investigated by theoretical calculation and experimental analysis. A finite element analysis (FEA) model of the rubber mount was developed and analyzed using the software MSC.MARC. FEA results imply that stress concentration may arise on the interfaces of the rubber layer and metal layer. Modifications were made to the structure parameters and rubber material of the rubber mount based on the analysis of FEA results. The stress concentration of the rubber mount at the rubber and metal interfaces was improved and the fatigue life of the improved rubber mount was increased. Finally, experiments were made to validate the accuracy of the FEA process and the reliability of the improved method. The proposed FEA and improved method can shorten the product design cycle, decrease the design and trial‐product cost and remarkably improve the product quality.     

Reaction cells and collision cells for ICP-MS: a tutorial review

This paper reviews the literature published to September 2001 relating to the history, design, operation and application of linear radio-frequency (r.f.)-driven multipole collision cells and reaction cells in combination with inductively coupled plasma mass spectrometry. The available material is supplemented with original experimental data that demonstrates the principles presented. The relation of these devices to collision cells for organic mass spectrometry and to the three-dimensional ion trap is discussed in its historical context. A general tutorial on the fundamentals of ion collision and reaction, including thermochemistry, energy transfer and reaction kinetics, is given. Consideration is given to some of the fundamental aspects of operation and design of linear r.f. devices. This historical and fundamental framework then allows the tutorial to focus on the promotion and control of ion–molecule chemistry in linear r.f.-multipole cells for elemental analysis. Vacuum requirements are considered in some detail, and deal in particular with the issue of contamination of the reaction gas. Special attention is paid to the thermal characteristics of the ions in the cell, as this has important implications for the application of the available databases of thermochemical and thermal kinetic data to the development of analytical methods. Calculation and experimental validation of the efficiency of the ion–molecule chemistry leads to the recognition that secondary, sequential chemistry can play a limiting role in the realization of the potential of the cell method. The two principal means of controlling the analytical impact of the secondary chemistry, through post-cell kinetic energy discrimination and through in-cell mass-bandpassing are discussed and contrasted through spectral data acquired for different reaction gas types and pressures. The available literature on the application of collision cells and reaction cells for the analysis of samples of high purity, environmental, geological and biological materials is critically reviewed.     

Macroscopic analysis of the behavior of colloidal suspensions

Three distinct and separate scales of discourse relevant to systems such as porous media and colloidal suspensions are identified: 1) the molecular scale; 2) the microscopic or Navier-Stokes scale; and 3) the macroscopic or Darcy scale. This article reviews the macroscopic mode of analysis which had its origins in problems of flow in porous media and which has been generalized and extended to apply to the behavior of colloidal suspensions. Applied to suspensions, the central concepts concern the energetics and hydrodynamics of the liquid phase.The approach leads to a non-linear Fokker-Planck equation, which reduces to a non-linear diffusion equation in some contexts. Simple experiments yield two functions characterizing the suspension. These functions express the dependence on particle volume fraction (or, equivalently, on ?, the ‘liquid ratio’) of ψ, the relevant chemical potential of the liquid, and κ, the permeability for flow relative to the particles. With these functions known, the analysis enables quantitative prediction of the time course of various flow, filtration, and sedimentation processes undergone by colloidal suspensions.The great generality and adaptability of the approach is emphasized. The necessary and sufficient condition for its application is simply that the characterizing functions exist and are measurable. The approach has been found to apply to a range of colloidal suspensions occurring in practical contexts in nature and industry. The analysis is free of the abstractions, simplifications, and assumptions required for quantitative theoretical studies on the molecular and microscopic scales. We may remain completely agnostic about particle shape, size distribution, and interactions. All information required is embodied in the ψ(?) and κ(?) functions.     

Matrix effects of easily ionizable elements and nitric acid in high-power microwave-induced nitrogen plasma atomic emission spectrometry

Matrix effects of Na, Ca and nitric acid in high-power microwave-induced nitrogen plasma atomic emission spectrometry were investigated with a number of atomic and ionic lines covering a wide range of energies. The plasma was sustained in an Okamoto cavity at atmospheric pressure by using nitrogen as the plasma gas as well as the nebulizer gas. Most of the atomic lines tested exhibited enhancement effects and all of the ionic lines gave suppression effects in the presence of Na and Ca. The effects decreased with increasing microwave power. There was good correlation between matrix effects, the excitation energy and energy sum of the spectral lines. The lower the excitation energy for atomic lines and the higher the energy sum for ionic lines, the stronger the matrix effects. Unlike Na and Ca, nitric acid showed suppression effect for all of the spectral lines and the effect was independent of the energy of the spectral lines and the microwave power. The effect of matrix on the excitation temperature and the electron number density was measured and the mechanism of matrix effect was discussed.     

自流平聚氨酯的制备及阻尼甲板的降噪性能

为降低船舶甲板的振动和空气噪声,以支化和线性多元醇,低粘度聚合多异氰酸酯(PMDI)为主要原料制得阻尼聚氨酯,并将其铺设于钢甲板与浮动甲板之间。 探讨了基体结构、阻尼填料等对阻尼层固化时间、流平、阻尼和力学等性能的影响,以及铺设阻尼层前后甲板整体的隔声性能。 结果表明,调节支链和线性多元醇的质量比,可以改变基体的交联程度与结构,支化多元醇提高了聚氨酯的固化速率,硬度,以及力学性能;线性多元醇降低了体系的玻璃化转变温度,使阻尼温域移向低温,损耗因子峰值提高。 铺设于现有浮动甲板结构下2 mm聚氨酯阻尼层,可以有效增加整个甲板平均3 dB的隔声量,且在低频区增加量更大。 制得的聚氨酯阻尼层流动性优越,室温固化时间可控,可方便快捷的一次性自流平施工,对于提高现有浮动甲板的降噪性能具有实际的意义。     

Development of a liquid chromatographic/tandem mass spectrometric assay for a new endothelin receptor antagonist,and its application to dog plasma samples generated after simultaneous i.v. and p.o. administration of the unlabeled and deuterium-labeled forms of this antagonist

An assay was developed and applied to determine the bioavailability of a new endothelin receptor antagonist after simultaneous p.o. and i.v. administration of the drug and its stable isotope-labeled analogue. The drug, its main metabolite and the stable isotope-labeled analogues of the drug and the main metabolite were quantified in dog plasma samples using a structural analogue as internal standard. In addition to the calculation of the bioavailability, the formation of the metabolite after p.o. and i.v. administration could be followed independently. The assay covered the concentration range 0.25-1000 ng ml(-1) using sample aliquots of only 50 micro l. Plasma samples were processed after protein precipitation with on-line solid-phase extraction, narrow-bore high-performance liquid chromatography and subsequent tandem mass spectrometric detection. Detection was accomplished with ionspray in the positive ion selected reaction monitoring mode. The inter-assay precision and accuracy of the assay were in the range 4.7-14.2% and 90.3-113.3%, respectively, and the intra-assay precision and accuracy were in the range 1.4-11.5% and 88.4-112.5%, respectively. The fragmentation of the drug was investigated and showed an unexpected shift of a methyl group. Data from MS(n), medium-resolution exact mass tandem mass spectrometry and H-D exchange experiments were employed to clarify the mechanism.     

The photophysics and photobiology of the eye

The eye consists of three major segments: the cornea, lens and retina. The main function of the anterior ocular tissue, the cornea and the lens is to transmit and focus light on the retina without distortion. They also filter out UV light (less than 400 nm) and prevent it from reaching the retina. Much of the light reaching the retina is used for sight. However, light can have numerous other effects on the constituents of the eye, both beneficial and deleterious. This article reviews the interaction of light with the eye, various protective mechanisms, the possible role of light in aging and disease states and the role of light in biological processes other than sight such as mood, hormonal secretions and the cyclic growth and phagocytosis of the rods and cones.