Poly(N‐isopropyl acrylamide) (pNIPAM) undergoes a sharp property change in response to a moderate thermal stimulus at physiologic temperatures. In this work, we constructed a radio frequency (RF) plasma reactor for the plasma polymerization of pNIPAM. RF deposition is a method that coats surfaces of any geometry producing surfaces that are sterile and uniform, making this technique useful for forming biocompatible films. The films generated are characterized using X‐ray photoelectron spectroscopy, contact angles, cell culture, and interferometry. We find that a plasma with a decreasing series of power settings (i.e., from 100 to 1 W) at a pressure of 140 mTorr yields the most favorable results.
Atmospheric pressure glow discharge plasma CVD was used to deposit thin films of titania at 200 °C using two different precursors. The resulting films were characterised using techniques including XPS, RBS and XRD. It was established that annealing at temperatures as low as 275 °C produced crystalline films that were photocatalytically active. When annealed at 300 °C the photoactivity was greater than that of commercially available “self‐cleaning” titania films. The effects of the different precursors, annealing times and temperatures on the crystallinity and photoactivity are discussed.
We review the derivation of generalised TAP equations for general quantum spin systems and apply the theory to a simple induced-moment spin glass model. We consider two-level systems with a singlet ground state and a triplet excited state, which interact via long range random exchange couplings. For not too large energy splitting the spin glass state can be stabilised. 相似文献
Analyte derivatization is advantageous for the analysis of malondialdehyde (MDA) as a biomarker of oxidative stress in biological samples. Conventionally, however, derivatization is time consuming, error-prone and has limited options for automation. We have addressed these challenges for the solid phase analytical derivatization of MDA from small volume tissue homogenate samples. A manual derivatization method was first developed using Amberlite XAD-2 (12 mg) as the solid phase. Subsequently an automated column switching process was developed that provided simultaneous derivatization and extraction of the MDA-DH hydrazone product on a cartridge packed with XAD-2, followed by quantitative elution of the product to an analytical LC column (Waters NovoPak C18, 3.9 x 150 mm). The LOD was 0.02 microg/mL and recovery was quantitative. The method was linear (r(2) >0.999) with precision < 5% from the LOQ (0.06 microg/mL) to at least 35 microg/mL. The method was successfully applied to the analysis of small volume (30 microL) mouse tissue homogenate samples. Endogenous levels of MDA in the tissues ranged from 20 to 40 nmol/g tissue (ca. 0.1-0.2 microg/mL homogenate). Compared to conventional MDA analyses, the current method has advantages in automation, selectivity, precision and sensitivity for analysis from very small sample volumes. 相似文献
A 1,8-bis(alkylamido)naphthalene framework has been applied to the construction of N-heterocyclic arsenium and stibenium cations; a novel synthetic route, involving protonation of an ancillary amido ligand, was used to generate the base-stabilized stibenium cation. 相似文献
