Synthesis and Characterization of Aminoporphyrin‐End‐Functionalized Poly(N‐isopropylacrylamide) with Photodynamic and Thermoresponsive Effects

The novel aminoporphyrin‐end‐functionalized poly(N‐isopropylacrylamide) (PNIPAM) polymer H₂N‐TPP‐PNIPAM (TPP=5,10,15,20‐tetraphenyl‐21H,23H‐porphyrin) behaves as a multifunctional platform that displays a photodynamic effect, thermosensitivity, and fluorescence properties. The polymer was designed by using an asymmetrical aminoporphyrin (i.e., H₂N‐TPP‐Cl) as the initiator for the atom‐transfer radical polymerization of N‐isopropylacrylamide (NIPAM). The polydispersity index (PDI) obtained by gel‐permeation chromatography indicated that the molecular‐weight distribution was narrow (1.09<PDI<1.27). The lower critical solution temperatures of H₂N‐TPP‐PNIPAM showed a decreasing trend as the molecular weight was increased as a result of the incorporation of the porphyrin group at the end of the chain. The fluorescence spectra revealed the luminescent properties of the materials. The results of confocal laser scanning microscopy showed that the polymer could enter the cytoplasm through endocytosis. In addition, the multifunctional platform exhibited low toxicity against normal cells (L929) and cancer cells (Hela) and enhanced photodynamic activity towards HeLa cells, without significant necrocytosis towards L929 cells; as a result this material may be useful in the future for practical photodynamic therapy.     

Linear {NiII–LnIII–NiII} Complexes Containing Twisted Planar Ni(μ‐phenolate)2Ln Fragments: Synthesis,Structure, and Magnetothermal Properties

Sequential reaction of a multisite LH₄ ligand {2‐[2‐hydroxy‐3‐(hydroxymethyl)‐5‐methylbenzylideneamino]‐2‐methylpropane‐1,3‐diol} with appropriate lanthanide salts followed by the addition of Ni(NO₃)₂ ? 6 H₂O in a 4:1:2 stoichiometric ratio in the presence of triethylamine afforded four heterobimetallic trinuclear complexes [Ni₂Gd(LH₃)₄] ? 3 NO₃ ? 3 MeOH ? H₂O ? CH₃CN ( 1 ), [Ni₂Tb(LH₃)₄] ? 3 NO₃ ? 3 MeOH ? CH₃CN ( 2 ), [Ni₂Dy(LH₃)₄] ? 3 NO₃ ? 3 MeOH ? H₂O ? CH₃CN ( 3 ), and [Ni₂Ho(LH₃)₄] ? 3 NO₃ ? 3 MeOH ? H₂O ? CH₃CN ( 4 ). Complexes 1 – 4 possess linear trimetallic cores with a central lanthanide ion. Magnetic studies revealed a predominant ferromagnetic interaction between the Ni and Ln centers. Alternating current susceptibility measurements of complex 3 showed a small frequency dependence of the out‐of‐phase signal, χ′′_M , under zero direct current field, but without achieving a net maximum above 2 K. Magnetic studies on 1 revealed that it has a significant magnetocaloric effect.     

Energetic Salts Based on an Oxygen‐Containing Cation: 2,4‐Diamino‐1,3,5‐triazine‐6‐one

A family of energetic salts with high thermal stability and low impact sensitivity based on an oxygen‐containing cation, 2,4‐diamino‐1,3,5‐triazine‐6‐one, were synthesized and fully characterized by IR and multinuclear (¹H, ¹³C) NMR spectroscopy, elemental analysis, and differential scanning calorimetry. Insights into their sensitivities towards impact, friction, and electrostatics were gained by submitting the materials to standard tests. The structures of 2,4‐diamino‐1,3,5‐triazine‐6‐one nitrate, 2,4‐diamino‐1,3,5‐triazine‐6‐one sulfate, 2,4‐diamino‐1,3,5‐triazine‐6‐one perchlorate, 2,4‐diamino‐1,3,5‐triazine‐6‐one 5‐nitrotetrazolate were determined by single‐crystal X‐ray diffraction; their densities are 1.691, 1.776, 1.854, and 1.636 g cm^?3, respectively. Most of the salts decompose at temperatures over 180 °C; in particular, the salts 2,4‐diamino‐1,3,5‐triazine‐6‐one nitrate and 2,4‐diamino‐1,3,5‐triazine‐6‐one perchlorate, which decompose at 303.3 and 336.4 °C, respectively, are fairly stable. Furthermore, most of the salts exhibit excellent impact sensitivities (>40 J), friction sensitivities (>360 N), and are insensitive to electrostatics. The measured densities of these energetic salts range from 1.64 to 2.01 g cm^?3. The detonation pressure values calculated for these salts range from 14.6 to 29.2 GPa, and the detonation velocities range from 6536 to 8275 m s^?1; these values make the salts potential candidates for thermally stable and insensitive energetic materials.     

Oxidation of aliphatic alcohols by triethylammonium chlorochromate in non-aqueous medium – A kinetic and mechanistic study

The oxidation of some aliphatic alcohols by triethylammonium chlorochromate (TriEACC) in dimethyl sulfoxide leads to the formation of the corresponding carbonyl compounds. The reaction is first order with respect to TriEACC. The reaction exhibited Michaelis–Menten type kinetics with respect to alcohol. The reaction is catalyzed by hydrogen ions. The hydrogen-ion dependence has the form: k_obs = a + b[H⁺]. The oxidation of [1,1-²H₂] ethanol (MeCD₂OH) exhibits a substantial primary kinetic isotope effect. Oxidation of aliphatic alcohol was studied in 19 different organic solvents. The solvent effect has been analysed using Kamlet’s and Swain’s multi-parametric equation. A suitable mechanism has been proposed.     

Development of Immunonutrient from Pumpkin (Cucurbita Moschata Duchense Ex. Lamk.) Seed

Pumpkin seeds has long been used as a source of nutrition. Based on its content, it is possible that part of this plant used as immunonutrient. The purpose of this research is to study the immunomodulatory activity of pumpkin seeds. It effects on the non-specific immune response was determined through carbon clearance test, organ indexes (liver, spleen and thymic gland) and mice peritoneal exudate activity (PEA). The effects on specific immune response were determined through total antibody titre, delayed type of hypersensitivity (DTH) reaction and number of lymphocytes. On non specific immune response test, pumpkin seed at a low dose (PLD-3.8 g/kg bw) and at a high dose (PHD-7.6 g/kg bw) showed immunostimulanting effect with phagocytic index of 1.219 and 1.347, respectively. PHD increased PEA activity (p<0.01) in lysing microbes. On specific immune response test, PLD and PHD showed immunostimulation effect indicated through 50% haemaglutination activity (HA titre) i.e., 1:512 and 1:2048, respectively compared to than that of control (1:256) for secondary antibody titre. Through cellular immunity test, 48 hours after challenged, PHD showed significant (p<0.05) increased in footpad thickness. After 7 days administration, both doses of pumpkin increased lymphocytes number significantly (p<0.05). Based on the data it can be concluded that, pumpkin seeds have immunomodulatory effects, and can therefore be used as immunonutrient     

Optofluidic droplet router

This contribution presents an optofluidic droplet router which is able to route and steer microdroplets using optically induced forces created solely by the bulk photovoltaic effect on a nonlinear substrate. The combination of microfluidic tools with the properties of a photorefractive crystal allows for the generation of dielectrophoretic forces that can be either repulsive, leading to virtual barriers, or attractive, creating virtual rails. The sign of these forces is solely determined by the electrical properties of the liquid medium under investigation. Moreover, the induced structures on the bottom of the microfluidic channel are optically reconfigurable, so that the same device can easily be adopted for different purposes. Appropriate droplet‐generating devices are fabricated by UV illumination of SU‐8 and polydimethylsiloxane replica molding of the master structures. The bottom of the channels is formed by an iron‐doped lithium niobate crystal, whose internal electric fields are induced by structured illumination patterns and exert dielectrophoretic forces on droplets in the microfluidic section.

     

高密度城区公园降温效应与模拟预测研究——以天津中心城区为例

在当前快速城镇化背景下,大量城镇人口导致各大城市人口密度不断增加,高密度的城区热岛现象开始加剧。公园绿地作为城市生态系统的重要组成部分,在缓解热岛方面具有重要作用。本研究以天津中心城区8处较大的公园绿地为实证对象,基于2013年Landsat8 ETM＋影像,通过单窗算法分析其降温效应。研究表明：公园面积及植被覆盖度是热岛效应最重要的影响因子,水体比例也在很大程度上影响着地表温度;各公园的最大降温强度和降温距离差异较大,降温强度温差约2．72℃,降温距离相差195 m;城区面积较大的公园降温效应更明显,水体比例高于30％或植被覆盖度高于10的公园降温效应较理想;并在研究结论的基础上构建了公园的降温效应模型。研究成果为天津中心城区及类似高密度城区的公园绿地规划提供了有效技术支撑。     

枯草芽孢杆菌微生态制剂在禽畜养殖中的作用

枯草芽孢杆菌作为一种绿色健康的微生态制剂,具有调节动物肠道平衡、促进营养吸收、提高免疫能力等功能。微生态制剂是抗生素的理想替代品之一,因其可有效防治动物疾病,并且无毒副作用,无残留污染,不产生抗药性,还能促进动物生长发育而在禽畜养殖中广泛应用。通过综述枯草芽孢杆菌的特性、作用机理以及枯草芽孢杆菌微生态制剂在禽畜养殖中的效果,分析了目前微生态制剂存在的问题及解决措施,并展望了其未来发展方向,为后续禽畜养殖提供借鉴和参考。     

Effect of agar hydrogel and magnesium ions on the biomimetic mineralization of calcium carbonate

Here, agar hydrogel was selected as diffusion medium and template to control the biomimetic mineralization of calcium carbonate (CaCO₃). Due to three dimensional network structures and abundant functional groups (such as, hydroxyl groups), Ca²⁺ ions were uniformly distributed in the network and electrostatically attracted. The diffusion speed and range of CO₃^2? ions were mediated by the concentration of hydrogel medium. Under the synergistic effect of Mg²⁺ ions, the crystal CaCO₃ was induced by gas phase diffusion method in the hydrogel system. The results showed that the concentrations of Mg²⁺ ions and agar hydrogel had no obvious effect on the calcite phase of CaCO₃, but the morphologies and sizes changed with concentrations of medium and Mg²⁺ ions. Attribute to template effect, the crystallization behavior and growth rate of CaCO₃ crystals were regulated. Since Mg²⁺ ions were easily adsorbed on the surfaces of unit cell, the unique structure of CaCO₃ was precisely controlled. This study provides a useful reference and inspiration for the understandings of the contributions of ion supply rate in bio-mineralization and hydrogel medium in biomimetic mineralization.