关于铁电体低维特性的研究

利用推广的Ginzhurg-Landeu-Devnnshire(GID)理论,研究不均匀结构对铁电体低维持性的影响。     

Three-dimensional mesomeric networks assembled from helix-linked sheets: syntheses, structures, and magnetisms

Two new three-dimensional nickel coordination polymers, [Ni3(BTC)2(4,4'-bpy)2(H2O)5].1.5H2O (1) and [Ni(PDB)(4,4'-bpy)].0.5H2O (2)(4,4'-bpy = bipyridine, BTC = 1,2,4-benzenetricarboxylate, PDB = pyridine-3,4-dicarboxylate), have been synthesized under hydrothermal conditions and characterized by elemental analysis, IR, TGA, and single crystal X-ray diffraction. Both compounds contain 2D scaffolding motifs, and most interestingly adjacent scaffolds are connected by infinite helical chains into unique three-dimensional mesomeric networks. Moreover, temperature-dependent magnetic susceptibilities for the two compounds were studied, and ferromagnetic interactions through syn-anti carboxylate bridges between Ni sites have been observed.     

Disulfide bond cleavage induced by a platinum(II) methionine complex

The cleavage of a disulfide bond and the redox equilibrium of thiol/disulfide are strongly related to the levels of glutathione (GSH)/oxidized glutathione (GSSG) or mixed disulfides in vivo. In this work, the cleavage of a disulfide bond in GSSG induced by a platinum(II) complex [Pt(Met)Cl2] (where Met = methionine) was studied and the cleavage fragments or their platinated adducts were identified by means of electrospray mass spectrometry, high-performance liquid chromatography, and ultraviolet techniques. The second-order rate constant for the reaction between [Pt(Met)Cl2] and GSSG was determined to be 0.4 M(-1) s(-1) at 310 K and pH 7.4, which is 100- and 12-fold faster than those of cisplatin and its monoaqua species, respectively. Different complexes were formed in the reaction of [Pt(Met)Cl2] with GSSG, mainly mono- and dinuclear platinum complexes with the cleavage fragments of GSSG. This study demonstrated that [Pt(Met)Cl2] can promote the cleavage of disulfide bonds. The mechanistic insight obtained from this study may provide a deeper understanding on the potential involvement of platinum complexes in the intracellular GSH/GSSG systems.     

Thermogravimetry study of the pyrolytic characteristics and kinetics of macro-algae Macrocystis pyrifera residue

Macrocystis pyrifera is one important marine macro-algae, while its residues produced by industrial alginate extraction is a hot potato. To figure out whether its residue is suitable for pyrolysis for biofuel, the pyrolytic characteristics and kinetics of macro-algae M. pyrifera residue was investigated using thermogravimetric method from 50 to 800 °C in an inert argon atmosphere at different heating rates of 5, 10, 20, and 30 °C min^?1. The activation energy and pre-exponential factor was calculated by Flynn–Wall–Ozawa, Kissinger–Akahira–Sunose, and Popescu methods, and the kinetic mechanism was deduced by Popescu method. The results showed that the primary devolatilization stage of M. pyrifera residue can be described by Jander function $ \left(\left[ {1 - \left( {1 - \alpha } \right)^{1/3} } \right]^{2}\right) $ . The average activation energy of M. pyrifera residue was 222.4 kJ mol^?1. The results suggested that the experimental results and kinetic parameters provided useful information for the design of pyrolytic processing system using M. pyrifera residue as feedstock.     

Ge—132对小鼠H22肝癌移植瘤的影响

Ｇｅ－１３２对小鼠Ｈ２２肝癌移植瘤的实验研究证明：１．Ｇｅ－１３２对Ｈ２２肝癌移植瘤有一定的抑制作用，３００ｍｇ／ｋｇ体重剂量抑瘤率达到３６．１９％；２．增强机体的抗氧化作用，抑制脂质的过氧化物水平；３．促进免疫功能，当Ｇｅ－１３２和环磷酰胺联合使用时，可抵抗环磷酰胺的免疫抑制作用，而且并不减弱其抑制瘤作用。     

Three New Neolignans and One New Phenylpropanoid from the Leaves and Stems of Toona ciliata var. pubescens

Three new neolignans, (7S,8S,7′E)‐4,9‐dihydroxy‐3,7,3′,9′‐tetramethoxy‐8,4′‐oxyneolign‐7′‐ene ( 1 ), (7R,8S,7′E)‐4, 9‐dihydroxy‐3,7,3′,9′‐tetramethoxy‐8,4′‐oxyneolign‐7′‐ene ( 2 ), (7S,8S,7′E)‐5, 9‐dihydroxy‐3,7,3′,5′,9′‐pentamethoxy‐8,4′‐oxyneolign‐7′‐ene ( 3 ), and one new phenylpropanoid, threo‐5‐hydroxy‐3,7‐dimethoxyphenylpropane‐8,9‐diol ( 4 ), were isolated from the leaves and stems of Toona ciliata var. pubescens. Their structures were determined on the basis of spectroscopic analysis, especially 2D‐NMR, HR‐ESI‐MS, and CD data. The antiproliferative activities of these compounds against four tumor cell lines (A549, Colo 205, QGY‐7703, and LOVO) were also evaluated by MTT (=(3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyl‐2H‐tetrazolium bromide) method.     

Oriental Lacquer. 10. The South East Asian Lacquer

Abstract

The family Anacardiaceae consists of 76 genera and about 600 species. A comparison of the species of Anacardiaceae is discussed with special emphasis on the importance of the exudates, the so-called sap, for their importance as lacquer to produce lacquer ware. Many exudates are poisonous. The individual chemical compounds which constitute the active ingredients of the oleoresin part of the sap and their function are described based on space-filling molecular models. Emphasis is also given to the organic components of lacquer trees of the South East Asian region, which is compared to other species of the Anacardiaceae family.     

Room Temperature Phosphorescence of 1-Bromo-4-(bromoacetyl)naphthalene Induced by Sodium Deoxycholate

Sodium deoxycholate (NaDOC) can induce 1-bromo-4-(bromoacetyl)naphthalene (BBAN) to undergo strong room temperature phosphorescence (RTP) without the removal of dissolved oxygen from the solution. RTP spectra, phosphorescence polarization and ¹³C NMR results, along with the molecular modeling calculations, supported the conclusion that BBAN molecule was combined in a sandwich with two NaDOC molecules by a “back-to-back” hydrophobic interaction arising from the apolar faces of the NaDOC molecules, which provided BBAN with a rigid enough microenvironment to produce RTP.     

Microfluidic synthesis of tunable poly-(N-isopropylacrylamide) microparticles via PEG adjustment

We present a microfluidic droplet method to synthesize a series of tunable poly(N-isopropylacrylamide) (PNIPAM) microparticles by the addition of polyethylene glycols (PEGs). The PEGs are used as porogens and could be removed simply by washing step. By varying molecular weights and concentrations of the PEGs, morphologies and temperature-sensitive properties of the formed PNIPAM microparticles are flexibly tuned. It is found that PEG of lower molecular weight induces smaller micropore sizes, and results in faster response rate. The volume changes prior to and after shrinkage can also be regulated by the addition of PEGs due to tuned homogeneities of micropores. The microparticles tuned by PEG1000 with ratio of added PEGs to NIPAM of 2:1 respond the fastest (120 s), whereas with ratio of added PEGs to NIPAM of 1:1 display largest volume change (1/γ=12.12). This simplicity and controllability of tunable microparticles synthesis are appealing for various applications ranging from chemical delivery, drug release control, to optical applications.