Photoinduced Electron Transfer Reactions for Macromolecular Syntheses.

Photochemical reactions, particularly those involving photoinduced electron transfer processes, establish a substantial contribution to the modern synthetic chemistry, and the polymer community has been increasingly interested in exploiting and developing novel photochemical strategies. These reactions are efficiently utilized in almost every aspect of macromolecular architecture synthesis, involving initiation, control of the reaction kinetics and molecular structures, functionalization, and decoration, etc. Merging with polymerization techniques, photochemistry has opened up new intriguing and powerful avenues for macromolecular synthesis. Construction of various polymers with incredibly complex structures and specific control over the chain topology, as well as providing the opportunity to manipulate the reaction course through spatiotemporal control, are one of the unique abilities of such photochemical reactions. This review paper provides a comprehensive account of the fundamentals and applications of photoinduced electron transfer reactions in polymer synthesis. Besides traditional photopolymerization methods, namely free radical and cationic polymerizations, step-growth polymerizations involving electron transfer processes are included. In addition, controlled radical polymerization and "Click Chemistry" methods have significantly evolved over the last few decades allowing access to narrow molecular weight distributions, efficient regulation of the molecular weight and the monomer sequence and incredibly complex architectures, and polymer modifications and surface patterning are covered. Potential applications including synthesis of block and graft copolymers, polymer-metal nanocomposites, various hybrid materials and bioconjugates, and sequence defined polymers through photoinduced electron transfer reactions are also investigated in detail.

Quality of abdominal ultrasound image acquisition by novice practitioners following a minimal training session on healthy volunteers.

BACKGROUND: Point of care ultrasound (POCUS) is an essential tool for physicians to guide treatment decisions in both hospital and prehospital settings. Despite the potential patient care and system utilization benefits of prehospital ultrasound, the financial burden of a "hands-on" training program for large numbers of paramedics remains a barrier to implementation. In this study, we conducted a prospective, observational, double-blinded study comparing paramedics to emergency physicians in their ability to generate usable abdominal ultrasound images after a 1-hour didactic training session. METHODS: Canadian aeromedical critical care paramedics were compared against emergency medicine physicians in their ability to generate adequate abdominal ultrasound images on five healthy volunteers. Quality of each scan was evaluated by a trained expert in POCUS who was blinded to the identity of the participant using a 5-point Likert scale and using the standardized QUICk Focused Assessment with Sonography in Trauma (FAST) assessment tool. RESULTS: Fourteen Critical care paramedics and four emergency department (ED) physicians were voluntarily recruited. Of paramedics, 57% had never used ultrasound before, 36% has used ultrasound without formal training, and 7% had previous training. Physicians had a higher proportion of usable scans compared with paramedics (100% v. 61.4%, Δ38.6%; 95% confidence interval, 19.3-50.28). CONCLUSIONS: Paramedics were not able to produce images of interpretable quality at the same frequency when compared with emergency medicine physicians. However, a 61.4% usable image rate for paramedics following a short 1-hour didactic training session is promising for future studies, which could incorporate a short hands-on tutorial while remaining cost-effective.

Abdominal ultrasound image acquisition and interpretation by novice practitioners after minimal training on a simulated patient model.

BACKGROUND: The Focused Assessment with Sonography in Trauma (FAST) exam is a rapid ultrasound test to identify evidence of hemorrhage within the abdomen. Few studies examine the accuracy of paramedic performed FAST examinations. The duration of an ultrasound training program remains controversial. This study's purpose was to assess the accuracy of paramedic FAST exam interpretation following a one hour didactic training session. METHODS: The interpretation of paramedic performed FAST exams was compared to the interpretation of physician performed FAST examinations on a mannequin model containing 300ml of free fluid following a one hour didactic training course. Results were compared using the Chi-square test. Differences in accuracy rate were deemed significant if p < 0.05. RESULTS: Fourteen critical care flight paramedics and four emergency physicians were voluntarily recruited. The critical care paramedics were mostly ultrasound-naive whereas the emergency physicians all had ultrasound training. The correct interpretation of FAST scans was comparable between the two groups with accuracy of 85.6% and 87.5% (∆1.79 95%CI -33.85 to 21.82, p = 0.90) for paramedics and emergency physicians respectively. CONCLUSIONS: This study determined that critical care paramedics were able to use ultrasound to detect free fluid on a simulated mannequin model and interpret the FAST exam with a similar accuracy as experienced emergency physicians following a one hour training course. This suggests the potential use of prehospital ultrasound to aid in the triage and transport decisions of trauma patients while limiting the financial and logistical burden of ultrasound training.

Selective Cell Adhesion and Biosensing Applications of Bio-Active Block Copolymers Prepared by CuAAC/Thiol-ene Double Click Reactions.

N-Acetyl-l-cysteine (NAC)-capped poly(methyl methacrylate)-b-polycaprolactone block copolymer (PMMA-b-PCL-NAC) was prepared using the previously described one-pot photoinduced sequential CuAAC/thiol-ene double click procedure. PMMA-b-PCL-NAC had previously shown good applicability as a matrix for cell adhesion of cells from the Vero cell line (African green monkey kidney epithelial). Here, in this work, PMMA-b-PCL-NAC served as an excellent immobilization matrix for biomolecule conjugation. Covalent binding of RGD (R: arginine, G: glycine, and D: aspartic acid) peptide sequence onto the PMMA-b-PCL-NAC-coated surface was performed via EDC chemistry. RGD-modified PMMA-b-PCL-NAC (PMMA-b-PCL-NAC-RGD) as a non-toxic cell proliferation platform was used for selective "integrin αvß3-mediated cell adhesion and biosensing studies. Both optical and electrochemical techniques were used to monitor the adhesion differences between "integrin αvß3" receptor positive and negative cell lines on to the designed biofunctional surfaces.