Nano-engineered optimal templates for surface-plasmon enhanced Raman scattering.

We investigated the critical conditions to realize reliable and nano-engineered templates for surface-plasmon enhanced Raman scattering (SERS). Ultra-sensitive SERSs of thymine oligonucleotides were successfully realized on the template of Au nanoparticle arrays which were prepared by the combination of electron-beam lithography and post-chemical modification techniques. Drastic enhancement of Raman signal from the thymine oligonucleotides was only observed on the optimized templates, where the tuning of the plasmon resonance condition and the formation of the hot spots were both critical. Our results suggest that the artificial generation of reproducible and controlled hot spots can be achieved by our approach.

Molecular characterization of Pseudomonas aeruginosa isolates resistant to all antimicrobial agents, but susceptible to colistin, in Daegu, Korea.

Multi-drug resistant Pseudomonas aeruginosa has been implicated in a variety of serious therapeutic problems in clinical environments. Among the 968 P. aeruginosa isolates obtained from two hospitals in Daegu, Korea, we acquired 17 isolates that were resistant to all available tested antimicrobial agents, with the exception of colistin (colistin-only sensitive). We characterized the antimicrobial susceptibilities, metallo-beta-lactamases, and epidemiological relatedness among the colistin-only sensitive P. aeruginosa isolates. All colistin-only sensitive isolates were positive in the modified Hodge test and imipenem-EDTA synergy test, thereby indicating the production of metallo-beta-lactamases. 11 isolates from the secondary hospital and six isolates from the tertiary teaching hospital harbored blaVIM-2 and blaIMP-1, respectively. The pulsed-field gel electrophoretic analysis of the SpeI-digested DNA from P. aeruginosa isolates indicated that two different clones of colistin-only sensitive P. aeruginosa originated from each hospital, and had spread within the hospital environment. Overall, colistin-only sensitive P. aeruginosa was detected in Korea for the first time, but no pan-drug resistant bacteria were identified. Nationwide surveillance is required in order to monitor the emergence of colistin-only sensitive or pan-drug resistant bacteria.

Reduction of intra-hospital transport time using the easy tube arrange device.

OBJECTIVE: Critically ill patients sometimes require transport to another location. Longer intra-hospital transport time increases the risk of hemodynamic instability and associated complications. Therefore, reducing intra-hospital transport time is critical. Our objective was to evaluate whether or not a new device the easy tube arrange device (ETAD) has the potential to reduce intra-hospital transport time of critically ill patients. METHODS: We enrolled volunteers for this prospective randomized controlled study. Each participant arranged four, five, and six fluid tubings, monitoring lines, and therapeutic equipment on a cardiopulmonary resuscitation training mannequin (Resusci Anne). The time required to arrange the fluid tubings for intra-hospital transport using two different methods was evaluated. RESULTS: The median time to arrange four, five, and six fluid tubings was 86.00 (76.50 to 98.50), 96.00 (86.00 to 113.00), and 115.50 (93.00 to 130.75) seconds, respectively, using the conventional method and 60.50 (52.50 to 72.75), 69.00 (57.75 to 80.80), and 72.50 (64.75 to 90.50) seconds using the ETAD (all P<0.001). The total duration (for preparing the basic setting and organizing before and after the transport) was 280.00 (268.75 to 293.00), 315.50 (304.75 to 330.75), and 338.00 (319.50 to 360.25) seconds for four, five, and six fluid tubings, respectively, using the conventional method and 274.50 (261.75 to 289.25), 288.00 (271.75 to 298.25), and 301.00 (284.50 to 310.75) seconds, respectively, using the new method (P=0.024, P<0.001, and P<0.001, respectively). CONCLUSION: The ETAD was convenient to use, reduced the time to arrange medical tubings, and is expected to assist medical staff during intra-hospital transport.

Solvent-free acid-catalyzed ring-opening of epoxidized oleochemicals using stearates/stearic acid, and its applications.

Toxic solvent and strong acid catalysts causing environmental issues have been mainly used for ring-opening of epoxidized oleochemicals. Here, we demonstrated that magnesium stearate (Mg-stearate) was a high efficient catalyst for solvent-free ring-opening of epoxidized methyl oleate, a model compound of midchain epoxide. Mg-stearate resulted in the highest yield (95%) and conversion rate (99%) toward midchain alkoxyesters under the same conditions (160 °C, 12 h) superior to other fatty acid derivatives such as a Lewis acid (lithium and sodium stearate) and Brønsted acid (stearic acid). Based on this chemical study, we synthesized biogrease and thermoplastic using epoxidized soybean oil (ESO) and Mg-stearate via one-pot, solvent-free, and purification-free process. Mg-stearate played a significant role as a reactant for epoxide ring-opening and as a thickener when excess loading rate was used; viscosity increased from 1800 to 4500 Pa·s at 25 °C when ESO:Mg-stearate increased from 1:1 equiv to 1:2, then behaved like thermoplastics (T(g) = -27 °C, T(m) = 90 °C) with 1:4.