蜂胶中具有抗氧化活性的木脂素

利用柱层析方法从蜂胶中分离得到了4种呋喃骈呋喃类木脂素，利用波谱学方法鉴定为芝麻脂素（sesamin）、yangambin、（＋）－松脂素[( )-pinoresinol]和（＋）－丁香脂素[( )-syringaresinol]，其中（＋）－松脂素和（＋）－丁香脂素为首次从蜂胶中得到。利用测定小鼠肝细胞微粒体脂质过氧化抑制作用的方法，检测了所得到的4种木脂素的抗氧化活性，其IC50值范围为9.0-14.0μg/ml。     

Articulating User Needs in Collaborative Design: Towards an Activity-Theoretical Approach

This paper analyses the collaborative design ofa high-technology product, a neuromagnetometerused in the analysis of the activity of thehuman cortex. The producer, Neuromag Company istrying to transform the device from a basicresearch instrument into a means of clinicalpractice. This transition is analyzed as asimultaneous evolution of the product,producer-user network and user activities. Thenetwork is analyzed as a network of activitysystems. Each activity has a historicallyformed object and a motive of its own, as wellas a system of cultural means and expertise. Weuse these to explain and understand theinterests and points of view of the actors inrelation to the product and the contradictionsof the producer-user network. It is suggestedthat the emerging user needs of collectiveactors must be analyzed at three levels. At thefirst level, the use value of the product, itscapacity of solving the vital problems andchallenges of developing user activities, ischaracterized. The second-level analysisconcerns the creation and development of thenecessary complementary tools and services thatmake the implementation and use of the productpossible. This task presupposes collaborationbetween several communities of the innovationnetwork. The third level is the situatedpractical use of the product. In ourexperience, it is advantageous that researcherscontribute with their data to a dialogue inwhich the user needs are articulated.     

Synthesis of some new 3-(2′-heterocyclicethyl)-2-methyl-3,4-dihydroquinazolin-4-one derivatives as antimicrobial agents

3-(2′-Chloroethyl)-2-methyl-3,4-dihydroquinazolin-4-one was reacted with acetylacetone, ethyl acetoacetate and diethylmalonate in the presence of sodium ethoxide to afford the alkylation products IV, V and VI , Compounds IV, V and VI were reacted with hydrazine hydrate, phenylhydrazine, hydroxylamine hydrochloride, urea and thiourea to yield 3-(2′-heterocyclicethyl)-2-methyl-3,4-dihydroquinazolin-4-one derivatives VII-XV . The structures of the synthesized compounds were elucidated by elemental analyses and spectroscopic (IR and XH-NMR) analyses. The prepared compounds were tested for their antimicrobial activities in comparison with tetracycline as a reference compound.     

Use of Response Surface Methodology to Investigate the Effectiveness of Commercial Enzymes on Buckwheat Malt for Brewing Purposes

The influence of two factors, total concentration and fraction of three pairs of commercial enzymes, which showed statistical significance (Biocellulase W with Hitempase 2XL, Biocellulase W with Amylo 300 and Amylo 300 with Hitempase 2XL), were studied for their overall effect on buckwheat wort quality using response surface methodology (RSM). This study revealed that the addition of increasing levels of Hitempase 2XL to the buckwheat mash increased colour, extract levels, wort filtration, fermentability and total fermentable extract (TFE), along with decreasing viscosity values. Results also determined a high level of fermentability when an enzyme combination of 30% Biocellulase and 70% Hitempase was added to the mash. The addition of increasing levels of Amylo 300 to buckwheat mashes resulted in increases in fermentability and total fermentable extract (TFE), along with increases in total soluble nitrogen (TSN), free amino nitrogen (FAN) and Kolbach index (KI). With regard to the proposed optimal regime, although no synergistic effect was found when the three enzymes were used together, the optimum conditions for the production of buckwheat wort with lowest viscosity, highest extract and optimal fermentability were achieved using a joint model. Overall, the findings of this study demonstrate the feasibility of producing wort suitable for the brewing of gluten‐free beer from 100% malted buckwheat with careful optimisation of enzyme types and dosage levels.     

Antioxidant activity of anacardic acids

Anacardic acids, 6-pentadec(en)ylsalicylic acids isolated from the cashew Anacardium occidentale L. (Anacardiaceae) nut and apple, were found to possess preventive antioxidant activity while salicylic acid did not show this activity. These anacardic acids prevent generation of superoxide radicals by inhibiting xanthine oxidase (EC 1.1.3.22, Grade IV) without radical-scavenging activity. Notably, the inhibition kinetics of anacardic acids do not follow hyperbolic dependence of enzyme inhibition on inhibitor contents (Michaelis–Menten equation) but follow the Hill equation instead. Anacardic acid (C_15:1) inhibited the soybean lipoxygenase-1 (EC 1.13.11.12, Type 1) catalyzed oxidation of linoleic acid with an IC₅₀ of 6.8 μM. The inhibition is a slow and reversible reaction without residual enzyme activity. The inhibition kinetics indicate that anacardic acid (C_15:1) is a competitive inhibitor and the inhibition constant, K_I, was 2.8 μM. Anacardic acids act as antioxidants in a variety ways, including inhibition of various prooxidant enzymes involved in the production of the reactive oxygen species and chelate divalent metal ions such as Fe²⁺ or Cu²⁺, but do not quench reactive oxygen species. The C₁₅-alkenyl side chain is largely associated with the activity.     

2，6-萘二甲酸二甲酯在有机溶剂中溶解度的测定与关联

Solubility of dimethyl-2,6-naphthalene dicarboxylate in acetic acid, N,N-dimethylfonnamide, N,N-dimethyl acetamide, dimethyl sulphoxide, and N-methyl-2-ketopyrrolidine were determined using a dynamic method. The measured systems were correlated by UNIFAC group contribution method. A new main group （aromatic ester, ACCOO） was defined to express the activity coefficients of the aromatic ester. New interaction parameters of the ACCOO group were expressed as the first-order function of temperature and were determined from the experimental data. The calculated results for the new interaction parameters were satisfactory. The measured systems were also correlated with the Wilson and 2-h models, and the results were compared with those of the UNIFAC model.     

膦化合物对加氢催化剂的影响

丁辛醇装置丁醛加氢催化剂在装置扩能投产以后热点上移 (失活 )的速率较快 ,针对催化剂老化的原因进行分析、判断 ,找出原因 ,采用相应的解决措施 ,可延长催化剂使用寿命 ,增加装置效益     

Hypnosis and clinical pain.

Hypnosis has been demonstrated to reduce analogue pain, and studies on the mechanisms of laboratory pain reduction have provided useful applications to clinical populations. Studies showing central nervous system activity during hypnotic procedures offer preliminary information concerning possible physiological mechanisms of hypnotic analgesia. Randomized controlled studies with clinical populations indicate that hypnosis has a reliable and significant impact on acute procedural pain and chronic pain conditions, Methodological issues of this body of research are discussed, as are methods to better integrate hypnosis into comprehensive pain treatment. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Design of a high-pressure ebulliometer,with vapor-liquid equilibrium results for the systems CHF2 Cl + CF3 CH3 and CF3 CH2 F + CH2F2

We describe the design and operation of a new high-pressure metal ebulliometer which can operate at pressures to at least 3 MPa in the range 220–400 K. Infinite-dilution activity coefficients are presented for the system CHF₂Cl + CF₃-CH, at 275 K and for the system CF₃-CH₂F + CH₂F₂, at 260, 230, and 300 K. The Wilson activity coellicient model and a virial coefficient model are applied to these systems, and the phase equilibrium conditions are calculated. The results are shown to agree well with predicted and with published measured values. The excess enthalpy is calculated and compared with results from a Peng Robinson equation of state. Vapor densities on the dew curves are given.