Chain-End Effects on Supramolecular Poly(ethylene glycol) Polymers.

In this work we present a fundamental analysis based on small-angle scattering, linear rheology and differential scanning calorimetry (DSC) experiments of the role of different hydrogen bonding (H-bonding) types on the structure and dynamics of chain-end modified poly(ethylene glycol) (PEG) in bulk. As such bifunctional PEG with a molar mass below the entanglement mass Me is symmetrically end-functionalized with three different hydrogen bonding (H-bonding) groups: thymine-1-acetic acid (thy), diamino-triazine (dat) and 2-ureido-4[1H]-pyrimidinone (upy). A linear block copolymer structure and a Newtonian-like dynamics is observed for PEG-thy/dat while results for PEG-upy structure and dynamics reveal a sphere and a network-like behavior, respectively.

Analgesia with interfascial continuous wound infiltration after laparoscopic colon surgery: A randomized clinical trial.

Objectives: For major laparoscopic surgery, as with open surgery, a multimodal analgesia plan can help to control postoperative pain. Placing a wound catheter intraoperatively following colon surgery could optimize the control of acute pain with less consumption of opioids and few adverse effects.

Methods: We conducted a prospective, randomized, study of patients scheduled to undergo laparoscopic colon surgery for cancer in Galdakao-Usansolo Hospital from January 2012 to January 2013.

Stimuli-responsive poly(4-vinyl pyridine) hydrogel nanoparticles: synthesis by nanoprecipitation and swelling behavior.

Stimuli-responsive polymer nanospheres of poly(4-vinyl pyridine) have been obtained using a very simple modified nanoprecipitation technique. This process is conducted without help of crosslinking or monomer polymerization, methods used until now for this purpose. The influence of the surfactant concentration used in the preparation on particle size, the stability and the swelling kinetics of these hydrogels are studied.