We report electrochemical and optical properties of the first electrochemically and chemically prepared green, soluble conducting polymer in its neutral form. Oxidative electrochemical and chemical polymerization of dioctyl-substituted 2,3-di(thien-3-yl)-5,7-di(thien-2-yl)thieno[3,4-b]pyrazine (3b) results in a soluble polymer (4b) with novel optical properties. The neutral polymer 4b absorbs both blue (above 600 nm) and red light (below 500 nm), reflecting a saturated green color. In the oxidized form, these absorptions are depleted, resulting in a transmissive pale brown polymer with very strong absorption in the near-infrared. Electrochemical and spectroelectrochemical semiconductor band gaps of 4b were found to be ca. 1.3 eV. Molecular weight analysis showed that soluble polymers have different conjugation length from oligomers to polymers. Since the monomer 3b has low oxidation potential (0.48 V vs Ag/Ag+), mild oxidizing agents (i.e., CuCl2) initiate chemical polymerization. The oxidant/monomer ratio should be at least 3:1 to get a desired green polymer. High green color saturation as well as the high solubility in common organic solvents makes this polymer a promising material to bring polymeric electrochromics closer to red, green, and blue (RGB) realization.

This US-guided method offers a new possibility for central venous line placement in small children. It provides good needle guidance without any disturbing US shadow caused by bony structures.

Background The aim of this retrospective analysis was to evaluate the clinical effectiveness of the supraclavicular ultrasound-guided cannulation of the brachiocephalic vein in preterm infants. Methods The ultrasound probe was placed in the supraclavicular region so as to obtain the optimum sonographic long-axis view of the brachiocephalic vein. By using a strict in-plane approach the brachiocephalic vein was cannulated by advancing a 22- or 24-gauge iv cannula from lateral to medial under the long axis of the ultrasound probe under real-time ultrasound guidance into the vein. Results One hundred and forty-two cannulations in infants weighing between 0.59 and 2.5 kg (median: 2.1; CI: 2.0 to 2.2) were included. Ultimate success rate was 94% (134 of 142). One cannulation attempt was required in 100 (70%) patients, two attempts in 21 (15%), and three attempts in 13 (9%). The smaller the weight of the infant the more attempts were needed. More attempts also were needed for the right brachiocephalic vein, which was primarily targeted in 75 (53%) neonates. One (1%) inadvertent arterial puncture was noted. Conclusions This supraclavicular, in-plane, real-time, ultrasound-guided cannulation of the brachiocephalic vein seems to be a convenient and effective method to insert central venous catheters in preterm infants.