混合型4自由度并联机构及其运动学建模

提出一种混合型４自由度并联平台机构，该机构的动平台能够实现两个方向的移动以及绕两个方向轴线的转动。研究了该机构的运动学建模方法，给出了运动学正、逆解。基于本文所提出的４自由度并联机构已成功地研制出一台五坐标并联机床。

一种4自由度混合型并联平台机器人

提出一种用水平导轨上4个滑块作为原动件的混合型4自由度并联平台机器人，该机器人的动平台能够实现两个方向的移动以及绕两个方向轴线的转动。研究了该机器人的运动学建模方法，给出了运动学正、逆解，用Grassman几何法分析了该机器人在其工作空间内不会出现奇异形位。基于该4自由度并联平台机器人可以非常方便地开发具有大工作空间的5轴联动数控机床。

4-6岁儿童对情绪表达规则的认知发展研究

情绪表达规则是指一个人应当在恰当的情境中表达恰当的情绪。对情绪表达规则的认知发展是个体社会能力发展的一个重要方面，因此这一主题引起了国内外众多研究者的重视。但目前对童年早期儿童的研究中，大多数只考查了儿童对情绪的外显表达与内隐真实体验的区分，没有同时考查儿童对需要使用情绪表达规则的情境的认知，不能全面真实地揭示儿童对情绪表达规则的认知发展。在本研究中，以个别访谈法考查了4－6岁儿童同一个体在这两个指标上对情绪表达规则认知的发展，以及发展中的个别差异和个体内部差异，并进一步了解情境因素以及心理理论能力、执行抑制能力的发展对它们的影响。主要结果如下： （1）4－6岁儿童对情绪表达规则的认知能力随年龄增长而提高：4岁尚处于发展的萌芽水平，5岁和6岁都处于发展的过渡水平。对于同一年龄的儿童，对情绪表达规则的认知发展存在较大的个体之间的差异。 （2）4－6岁儿童对情绪表达规则的认知也存在较大的个体内部差异：对表情伪装的认知滞后于对需要使用情绪表达规则的情境的认知，对言语伪装的认知优于对表情伪装的认知；在对情绪表达规则的使用中，自我定向的占多数，其次是他人定向，规则定向所占的比例最少。随年龄的增长，自我定向的比例减少，他人定向的比例增多。 （3）情境变量影响4－6岁儿童对情绪表达规则的认知：与同伴交往情境中对需要使用情绪表达规则的情境的认知、对言语伪装的认知优于与长辈交往情境中的有关认知；对需要掩藏消极情绪情境中对表情伪装的认知要优于对需要掩藏积极情绪情境中表情伪装的认知。 （4）4－6岁儿童心理理论能力的发展和执行抑制能力的发展与其对情绪表达规则的认知发展有关。 （5）有关情绪表达规则的提示能够促进儿童对情绪隐私的认知，促进的效果随年龄的增长而提高，6岁的效果最好。

从看图讲故事看4-7岁儿童创造力的发展及其入学突降现象

创造力发展的年龄特征一直是研究者非常关注的问题。很多研究者认为，只有更全面地探查儿童创造力的发展，才能充分了解创造力的本质，所以，应该在多个领域中研究创造力。本研究以文学领域中儿童比较熟悉并喜欢的讲故事的形式，采用同感评估技术（CAT），对4-7岁儿童的创造力发展趋势进行了研究，并深入探讨了经常被人们提到的出现在该阶段中的“入学突降”现象。研究共分为两个部分：研究一考察了4-7岁儿童创造力的发展趋势和创造力的“入学突降”现象；研究二探查了讲故事任务的创造力与言语能力的关系，讨论了创造力的领域特殊性。研究结果发现： 1. 4-7岁儿童的创造力随年龄的增长总体上表现出先上升后下降的趋势，并且存在性别差异。性别差异的具体表现为，女生在4-5岁的发展快于男生，且在6岁开始出现下降趋势。 2. 排除入学影响，随年龄增长，6-7岁儿童的创造力显著上升。 3. 6岁已入学儿童的创造力显著低于同年龄未入学儿童，其中女生受到的影响更大。 4. 言语能力是讲故事创造力的基础，只有达到了一定水平的言语能力才能够表现出较高水平的创造力，但是言语能力只是讲故事创造力的必要而非充分条件。 5. 研究结果部分支持了创造力领域特殊性的理论。

Simulation chamber studies of the atmospheric degradation of naphthalene, 1-nitronaphthalene and phthaldialdehyde

A detailed series of simulation chamber experiments has been performed on the atmospheric degradation pathways of the primary air pollutant naphthalene and two of its photooxidation products, phthaldialdehyde and 1-nitronaphthalene. The measured yields of secondary organic aerosol (SOA) arising from the photooxidation of naphthalene varied from 6-20%, depending on the concentrations of naphthalene and nitrogen oxides as well as relative humidity. A range of carbonyls, nitro-compounds, phenols and carboxylic acids were identified among the gas- and particle-phase products. On-line analysis of the chemical composition of naphthalene SOA was performed using aerosol time-of-flight mass spectrometry (ATOFMS) for the first time. The results indicate that enhanced formation of carboxylic acids may contribute to the observed increase in SOA yields at higher relative humidity. The photolysis of phthaldialdehyde and 1-nitronaphthalene was investigated using natural light at the European Photoreactor (EUPHORE) in Valencia, Spain. The photolysis rate coefficients were measured directly and used to confirm that photolysis is the major atmospheric loss process for these compounds. For phthaldialdehyde, the main gas-phase products were phthalide and phthalic anhydride. SOA yields in the range 2-11% were observed, with phthalic acid and dihydroxyphthalic acid identified among the particle phase products. The photolysis of 1-nitronaphthalene yielded nitric oxide and a naphthoxy radical which reacted to form several products. SOA yields in the range 57-71% were observed, with 1,4-naphthoquinone, 1-naphthol and 1,4-naphthalenediol identified in the particle phase. On-line analysis of the SOA generated in an indoor chamber using ATOFMS provided evidence for the formation of high-molecular-weight products. Further investigations revealed that these products are oxygenated polycyclic compounds most likely produced from the dimerization of naphthoxy radicals. These results of this work indicate that naphthalene is a potentially large source of SOA in urban areas and should be included in atmospheric models. The kinetic and mechanistic information could be combined with existing literature data to produce an overall degradation mechanism for naphthalene suitable for inclusion in photochemical models that are used to predict the effect of emissions on air quality.

Water vapor line parameters in the 13 000-9250 cm-1 region.

info:eu-repo/semantics/published

Enhanced cAMP generation and insulin-releasing potency of two novel Tyr(1)-modified enzyme-resistant forms of glucose-dependent insulinotropic polypeptide is associated with significant antihyperglycaemic activity in spontaneous obesity-diabetes

Glucose-dependent insulinotropic polypeptide (GIP) is an important incretin hormone, which potentiates glucose-induced insulin secretion. Antihyperglycaemic actions of GIP provide significant potential in Type 11 diabetes therapy. However, inactivation of GIP by the enzyme dipeptidyl peptidase IV (DPP IV) and its consequent short circulating half-life limit its therapeutic use. Therefore two novel Tyr(1)-Modified analogues of GIP, N-Fmoc-GIP (where Fmoc is 9-fluorenylmethoxycarbonyl) and N-palmitate-GIP, were synthesized and tested for metabolic stability and biological activity. Both GIP analogues were resistant to degradation by DPP IV and human plasma. In Chinese hamster lung (CHL) cells expressing the cloned human GIP receptor, both analogues exhibited a 2-fold increase in cAMP-generating potency compared with native GIP (EC50 values of 9.4, 10.0 and 18.2 nM respectively). Using clonal BRIN-BD11 cells, both analogues demonstrated strong insulinotropic activity compared with native GIP (P <0.01 to P <0.001). In obese diabetic (ob/ob) mice, administration of N-Fmoc-GIP or N-palmitate-GIP (25 nmol/kg) together with glucose (18 mmol/kg) significantly reduced the peak 15 min glucose excursion (1.4- and 1.5-fold respectively; P <0.05 to P <0.01) compared with glucose alone. The area under the curve (AUC) for glucose was significantly lower after administration of either analogue compared with glucose administered alone or in combination with native GIP (1.5-fold; P <0.05). This was associated with a significantly greater AUC for insulin (2.1-fold; P <0.001) for both analogues compared with native GIP. A similar pattern of in vivo responsiveness was evident in lean control mice. These data indicate that novel N-terminal Tyr(1) modification of GIP with an Fmoc or palmitate group confers resistance to degradation by DPP IV in plasma, which is reflected by increased in vitro potency and greater insulinotropic and antihyperglycaemic activities in an animal model of Type 11 diabetes mellitus.

Unusual voltammetry of the reduction of O-2 in [C(4)dmim][N(Tf)(2)] reveals a strong interaction of O-2(center dot-) with the [C(4)dmim](+) cation

Voltammetric studies of the reduction of oxygen in the room temperature ionic liquid [C(4)dmim][N(Tf)(2)] have revealed a significant positive shift in the back peak potential, relative to that expected for a simple electron transfer. This shift is thought to be due to the strong association of the electrogenerated superoxide anion with the solvent cation. In this work we quantitatively simulate the microdisc electrode voltammetry using a model based upon a one-electron reduction followed by a reversible chemical step, involving the formation of the [C(4)dmim](+)center dot center dot center dot O-2(center dot-) ion-pair, and in doing so we extract a set of parameters completely describing the system. We have simulated the voltammetry in the absence of a following chemical step and have shown that it is impossible to simultaneously fit both the forward and reverse peaks. To further support the parameters extracted from fitting the experimental voltammetry, we have used these parameters to independently simulate the double step chronoamperometric response and found excellent agreement. The parameters used to describe the association of the O-2(center dot-) with the [C(4)dmim](+) were k(f) = 1.4 x 10(3) s(-1) for the first-order rate constant and K-eq = 25 for the equilibrium constant.

An electrochemical study of PCl3 and POCl3 in the room temperature ionic liquid [C(4)mpyrr][N(Tf)(2)]

Voltammetric studies of PCl3 and POCl3 have not been reported in the literature to date, probably due to the instability of these molecules in conventional aprotic solvents giving unstable and irreproducible results. From a previous study [Amigues et al. Chem. Commun. 2005, 1-4], it was found that ionic liquids have the ability to offer a uniquely stable solution phase environment for the study of these phosphorus compounds. Consequently, the electrochemistry of PCl3 and POCl3 has been studied by cyclic voltammetry on a gold microelectrode in the ionic liquid [C(4)mpyrr][N(Tf)(2)] (1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl) imide). For both compounds, reduction and oxidation waves were observed and a tentative assignment of the waves is given. For PCl3, the reduction was thought to proceed via the following mechanism: PCl3 + e(-) h reversible arrow PCl3-, PCl3- reversible arrow Cl- + (PCl2)-Cl-center dot, (and) Cl- + PCl3 h PCl4-. For POCl3, the suggested reduction mechanism was analogous to that of PCl3: POCl3 + e(-) reversible arrow POCl3-, POCl3- reversible arrow Cl- + (POCl2)-O-center dot, and Cl- + POCl3 h POCl4-. In both cases (PCl2)-Cl-center dot and (POCl2)-O-center dot are likely to engage in further reactions. Potential step microdisk chronoamperometry was carried out on the reductive waves of PCl3 and POCl3 to measure diffusion coefficients and number of electrons transferred. It was found that the diffusion of PCl3 was unusually slow (3.1 x 10(-12) m(2) s(-1)): approximately 1 order of magnitude less than that for POCl3 (2.2 x 10(-11) m(2) s(-1)). For both PCl3 and POCl3, a

Kinetic analysis of the reaction between electrogenerated superoxide and carbon dioxide in the room temperature ionic liquids 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide and hexyltriethylammonium bis(trifluoromethylsulfonyl)imide

The reduction of oxygen in the presence of carbon dioxide has been investigated by cyclic voltammetry at a gold microdisk electrode in the two room-temperature ionic liquids 1-ethyl-3-methylimidazolium bis-(trifluoromethylsulfonyl)imide ([EMIM][N(Tf)(2)]) and hexyltriethylammonium bis(trifluoromethylsulfonyl)imide ([N-6222] [N(Tf)(2)]). With increasing levels of CO2, cyclic voltammetry shows an increase in the reductive wave and diminishing of the oxidative wave, indicating that the generated superoxide readily reacts with carbon dioxide. The kinetics of this reaction are investigated in both ionic liquids. The reaction was found to proceed via a DISP1 type mechanism in [EMIM][N(Tf)(2)] with an overall second-order rate constant of 1.4 +/- 0.4 x 10(3) M-1 s(-1). An ECE or DISP1 mechanism was determined to be the most likely pathway for the reaction in [N-6222][N(Tf)(2)], with an overall second-order rate constant of 1.72 +/- 0.45 x 10(3) m(-1) s(-1).

Herpes simplex virus type 1 and Alzheimer's disease: the autophagy connection.

The causes of Alzheimer's disease (AD) and of the characteristic pathological features—amyloid plaques and neurofibrillary tangles—of AD brain are unknown, despite the enormous resources provided over the years for their investigation. Indeed, the only generally accepted risk factors are age, Down syndrome, carriage of the type 4 allele of the apolipoprotein E gene (APOE-e 4), and possibly brain injury. Following the authors' previous studies implicating herpes simplex virus type 1 (HSV1) in brain of APOE-e 4 carriers as a major cause of AD, the authors propose here, on the basis of their and others' recent studies, that not only does HSV1 generate the main components of amyloid plaques and neurofibrillary tangles (NFTs)—ß -amyloid (Aß) and abnormally phosphorylated tau but also, by disrupting autophagy, it prevents degradation of these aberrant proteins, leading to their accumulation and deposition, and eventually to AD.

Temperature Dependence of the Primary Relaxation in 1-Hexyl-3-methylimidazolium bis{(trifluoromethyl)sulfonyl}imide

We present results from complementary characterizations of the primary relaxation rate of a room temperature ionic liquid (RTIL), 1-hexyl-3-methylimidazolium bis{(trifluoromethyl)sulfonyl} imide, [C(6)mim][Tf2N], over a wide temperature range. This extensive data set is successfully merged with existing literature data for conductivity, viscosity, and NMR diffusion coefficients thus providing, for the case of RTILs, a unique description of the primary process relaxation map over more than 12 decades in relaxation rate and between 185 and 430 K. This unique data set allows a detailed characterization of the VTF parameters for the primary process, that are: B = 890 K, T-0 = 155.2 K, leading to a fragility index m = 71, corresponding to an intermediate fragility. For the first time neutron spin echo data from a fully deuteriated sample of RTIL at the two main interference peaks, Q = 0.76 and 1.4 angstrom(-1) are presented. At high temperature (T > 250 K), the collective structural relaxation rate follows the viscosity behavior; however at lower temperatures it deviates from the viscosity behavior, indicating the existence of a faster process.

Visible-light-sensitized near-infrared luminescence from rare-earth complexes of the 9-hydroxyphenalen-1-one ligand

The unique absorption properties of the 9-hydroxyphenalen-1-one (HPHN) ligand have been exploited to obtain visible-light-sensitizable rare-earth complexes in 1: 3 and 1: 4 metal-to-ligand ratios. In both stoichiometries (1:3,tris,Ln(PHN)3;1:4, tetrakis, A[ Ln( PHN)(4)], with Ln being a trivalent rare-earth ion and A being a monovalent cation), the complexes of Nd(III),Er( III), and Yb(III) show typical near-infrared luminescence upon excitation with visible light with wavelengths up to 475 nm. The X-ray crystal structures of the tris complexes show solvent coordination to the central rare-earth ion, whereas in the tetrakis complexes, the four PHN-ligands form a protective shield around the central ion, preventing small solvent molecules from coordinating to the rare-earth ion, at least in the solid state.

Facile biocatalytic reduction of the carbon-carbon double bond of 5-benzylidenethiazolidine-2,4-diones. Synthesis of ( )-5-(4-{2-[methyl(2-pyridyl)amino]ethoxy}benzyl)thiazolidine-2,4-dione (BRL 49653), its (R)-(+)-enantiomer and analogs.

Cantello, Barrier C. C.; Eggleston, Drake S.; Haigh, David; Haltiwanger, R. Curtis; Heath, Catherine M.; Hindley, Richard M.; Jennings, Keith R.; Sime, John T.; Woroniecki, Stefan R. SmithKline Beecham Pharmaceuticals, Surrey, UK. Journal of the Chemical Society, Perkin Transactions 1: Organic and Bio-Organic Chemistry (1994), (22), 3319-24. Publisher: Royal Society of Chemistry, CODEN: JCPRB4 ISSN: 0300-922X. Journal written in English. CAN 122:105736 AN 1995:237497 CAPLUS (Copyright (C) 2009 ACS on SciFinder (R)) Abstract A novel biotransformation system for the redn. of carbon-carbon double bonds in 5-benzylidenethiazolidine-2,4-diones to give the corresponding 5-benzylthiazolidine-1,4-diones, using whole cells of red yeasts, is described. These reduced compds., which are recovered in good yield, are of potential use in the treatment of non-insulin dependent diabetes mellitus. The mild reaction conditions developed allow redn. of 5-benzylidenethiazolidine-2,4-diones contg. other functionalities which are not compatible with alternative redn. methods. The biocatalytic redn. is enantioselective and the synthesis of R-(+)-5-(4-{2-[methyl(2-pyridyl)amino]ethoxy}benzyl)thiazolidine-2,4-dione by Rhodotorula rubra CBS 6469 and structure confirmation by X-ray crystallog. is detailed. Optimization of reaction conditions (including immobilization) for these whole cell redn. system is described.