电位滴定分析ASP驱采出液中表面活性剂浓度

以十二烷基磺酸钠为例,考察了利用电位滴定方法分析ASP三元复合驱采出液中表面活性剂浓度时,pH值、盐度、聚合物含量、石油酸皂浓度等因素对分析结果的影响,研究出因石油酸皂和聚合物的存在导致结果偏高的消除方法,并对方法的检出限进行研究。该方法为ASP三元驱中十二烷基磺酸钠类阴离子表面活性剂浓度的分析提供了参考。     

Tuning Physicochemical Properties of a Macroporous Polysaccharide-Based Scaffold for 3D Neuronal Culture

Central nervous system (CNS) lesions are a leading cause of death and disability worldwide. Three-dimensional neural cultures in biomaterials offer more physiologically relevant models for disease studies, toxicity screenings or in vivo transplantations. Herein, we describe the development and use of pullulan/dextran polysaccharide-based scaffolds for 3D neuronal culture. We first assessed scaffolding properties upon variation of the concentration (1%, 1.5%, 3% w/w) of the cross-linking agent, sodium trimetaphosphate (STMP). The lower STMP concentration (1%) allowed us to generate scaffolds with higher porosity (59.9 ± 4.6%), faster degradation rate (5.11 ± 0.14 mg/min) and lower elastic modulus (384 ± 26 Pa) compared with 3% STMP scaffolds (47 ± 2.1%, 1.39 ± 0.03 mg/min, 916 ± 44 Pa, respectively). Using primary cultures of embryonic neurons from PGK^Cre, Rosa26^tdTomato embryos, we observed that in 3D culture, embryonic neurons remained in aggregates within the scaffolds and did not attach, spread or differentiate. To enhance neuronal adhesion and neurite outgrowth, we then functionalized the 1% STMP scaffolds with laminin. We found that treatment of the scaffold with a 100 μg/mL solution of laminin, combined with a subsequent freeze-drying step, created a laminin mesh network that significantly enhanced embryonic neuron adhesion, neurite outgrowth and survival. Such scaffold therefore constitutes a promising neuron-compatible and biodegradable biomaterial.     

Effects of cellular fine structure on scattered light pattern

Biological cells are complex in both morphological and biochemical structure. The effects of cellular fine structure on light scattered from cells are studied by employing a three-dimensional code named AETHER which solves the full set of Maxwell equations by using the finite-difference time-domain method. It is shown that changes in cellular fine structure can cause significant changes in the scattered light pattern over particular scattering angles. These changes potentially provide the possibility for distinguishability of cellular intrastructures. The effects that features of different intrastructure have on scattered light are discussed from the viewpoint of diagnosing cellular fine structure. Finally, we discuss scattered light patterns for lymphocyte-like cells and basophil-like cells.     

One Step Synthesis of Gold‐Loaded Radial Mesoporous Silica Nanospheres and Supported Lipid Bilayer Functionalization: Towards Bio‐Multifunctional Sensors

A simple synthetic route is developed to achieve gold functionalized radial mesoporous silica nanoparticles (Au‐MsNP) synthesized by a one step procedure fully compatible with basic conditions required for the preparation of monodispersed nanospheres. In a second step, Au‐MsNP particles have been coated with phospholipid bilayers in order to design an advanced biofunctional platform with the gold metallic nanoparticles previously grown into the pore channels and responsible for a plasmonic activity relevant for biosensing. The size of Au‐MsNP is checked by dynamic light scattering while zeta potential measurements reflect their surface charge. The particle morphology is characterized by transmission and scanning electron microscopy and the Si/Au ratios are obtained from energy dispersive X‐ray analysis. The textural properties of Au‐MsNP, specific surface area and pore size, are determined from N₂ adsorption. The supported bilayers are achieved from vesicles of different phospholipids incubated with Au‐MsNP particles. The coating efficiency is investigated by zeta potential and cryo‐ transmission electron microscopy. The plasmonic activities of bare Au‐MsNP particles and coated lipid bilayer Au‐MsNP platform are evidenced for two model systems: direct adsorption of bovine serum albumin and molecular recognition events between avidin molecules and biotin receptors integrated in the supported lipid bilayer.     

Hydrophilization by coating of silylated polyoxazoline using sol–gel process

Hybrid films prepared from TEOS and polyoxazolines (Si–POx–Si) crosslinking agents were coated on different substrates in order to modify their surface properties. The film cohesion and adhesion on substrates were expected through the hydrogen bonding of the polyoxazoline crosslinked network. Low molecular-weight α,ω-unsaturated polyoxazolines (DA-PMOx)s were synthesized by a one step cationic ring-opening polymerization (CROP) of 2-methyl-2-oxazoline (MOx) with a good control over the molecular weight. Based on double thiol-ene coupling (d-TEC) a post-functionalization of DA-PMOx end chains gave in good yield polyoxazoline cross linker (Si–POx–Si). Glass and various polymer substrates (PP, PEI, POM, etc.) were spin coated by the organic–inorganic hybrid films through sol–gel process. AFM, SEM, visible reflectance spectroscopy and contact angle experiments allowed the full characterization of targeted surfaces and demonstrated the efficiency of the polyoxazoline coating.     

Combined BS and MS Degree Program in Architectural Engineering

This paper describes the implementation of a combined bachelor of science and master of science degree program in architectural engineering at Kansas State University (KSU). The BS degree in architectural engineering at KSU is a five-year, 162-credit program. Students accepted into the combined BS∕MS program have the potential to reduce their undergraduate program by 15 complementary and free electives and then complete a 30-credit MS program. Availability of the program has contributed to a significant increase in the number and quality of graduate students with the potential to make a significant contribution in the building industry.     

Effect of secondary alcohol ethoxylates on behavior of triolein-water-surfactant systems

Study of the equilibrium phase behavior of systems containing water, triolein and secondary alcohol ethoxylates showed that a D or microemulsion phase, which solubilized significant amounts of triolein, formed at temperatures as low as 25°C when the surfactant was a suitable mixture of TERGITOL 15-S-3 and 15-S-5 (Union Carbide, Charleston, WV) with average ethylene oxide numbers of 3 and 5, respectively. In previous work with pure C₁₂ linear ethoxylates and triolein, the D phase had formed only at temperatures above about 55°C. Based on the earlier studies, formation of the D phase would be expected to improve soil removal from synthetic fabrics by a solubilization-emulsification mechanism. When sufficient oleyl alcohol was mixed with triolein, the D phase was observed at 25°C with Tergitol 15-S-5 alone. Observation of dynamic behavior in this system for triolein-oleyl alcohol drops injected into surfactant-water mixtures revealed that intermediate phases frequently formed near the drop surfaces and that considerable spontaneous emulsification of triolein occurred for appropriate drop compositions. Experiments with drops initially attached to individual polyester fibers confirmed that little oil remained on the fibers when emulsification was extensive. This mechanism involving spontaneous emulsification provides a means for soil removal different from that found previously in other systems, where the soil was solubilized into an intermediate phase, and this phase was emulsified by externally imposed agitation.