3 research outputs found
Studies of phase separable soluble polymers
The technique of phase labeling has the ability to greatly enhance synthetic
protocol by simplifying purification and increasing efficiency. Traditional insoluble
supports offer efficient and simple recovery of the Ăphase taggedĂ material but suffer
from problems inherent to their heterogeneous nature. A solution to these problems has
been to utilize phase separable soluble polymers in the design of ĂsmartĂ responsive
systems that offer the option of homogenous reaction conditions with heterogeneous
separation conditions. The subject of this dissertation focuses on the application of
soluble polymeric phase tags in systems where the miscibility between solid-liquid and
liquid-liquid systems is thermally induced.
Low molecular weight poly(ethylene glycol) (PEG) oligomers were investigated
as phase anchors for SCS palladacycle catalysts. The oligomeric PEG chains were
sufficient to engender polar phase solubility in a heptane-DMA thermomorphic system.
Microwave irradiation of these thermomorphic mixtures of palladium complexes and
substrates was a viable scheme to recycle and significantly shorten reaction times for
simple Heck reactions of aryl iodides. Soluble polymeric supports possessing a lower critical solution temperature
(LCST) were utilized in the sequestration of the S-triazine herbicide, atrazine, from
contaminated water samples. The ability of poly(N-isopropylacrylamide) to sequester
hydrophobic guests like atrazine was examined. A functionalized PNIPAM derivative
containing secondary cyclic amines exhibited superior sequestration ability that was
credited to the covalent binding of the atrazine.
In order to facilitate the design of tailored, thermally responsive, smart polymers,
a high throughput temperature gradient microfluidic device was used to obtain LCST
data in a fast, accurate manner. The specific ion effects of various alkali metal halide
salts on the LCST of PNIPAM were investigated. The high precision in the
measurements enabled more subtle effects such as changes in solvent isotope, polymer
microstructure, molecular weight, and importance of end group effects on the LCST of
poly(N-alkylacrylamide)s to be evaluated
Get with the guidelines: management of chronic obstructive pulmonary disease in emergency departments in Europe and Australasia is subâoptimal
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Preferred learning modalities and practice for critical skills: A global survey of paediatric emergency medicine clinicians
© Author(s) (or their employer(s)) 2019. No commercial re-use. See rights and permissions. Published by BMJ. Objective To describe senior paediatric emergency clinician perspectives on the optimal frequency of and preferred modalities for practising critical paediatric procedures. Methods Multicentre multicountry cross-sectional survey of senior paediatric emergency clinicians working in 96 EDs affiliated with the Pediatric Emergency Research Network. Results 1332/2446 (54%) clinicians provided information on suggested frequency of practice and preferred learning modalities for 18 critical procedures. Yearly practice was recommended for six procedures (bag valve mask ventilation, cardiopulmonary resuscitation (CPR), endotracheal intubation, laryngeal mask airway insertion, defibrillation/direct current (DC) cardioversion and intraosseous needle insertion) by at least 80% of respondents. 16 procedures were recommended for yearly practice by at least 50% of respondents. Two procedures (venous cutdown and ED thoracotomy) had yearly practice recommended b