Carbon nanotube-assisted enhancement of surface plasmon resonance signal.

We describe a method of amplifying the biosensing signal in surface plasmon resonance (SPR)-based immunoassays using an antibody-carbon nanotube (CNT) conjugate. As a model system, human erythropoietin (EPO) and human granulocyte macrophage colony-stimulating factor (GM-CSF) were detected by sandwich-type immunoassays using an SPR biosensor. For the amplification of the SPR signal, the CNT was conjugated with a polyclonal antibody, and then the conjugates were reacted with antibodies coupled with the target proteins. This amplification strategy increases the dynamic range of the immunoassays and enhances the detection sensitivity. The SPR immunoassays, combined with the CNT-assisted signal amplification method, provided a wide dynamic range over four orders of magnitude for both EPO and GM-CSF (0.1-1,000 ng/ml). The CNT amplification method is expected to realize the detection of picogram levels and a wide dynamic detection range of multiple proteins, enabling it to offer a robust analysis tool for the development of biopharmaceutical production.

The education and practice program for medical students with quantitative and qualitative fit test for respiratory protective equipment.

Tuberculosis infection is prevalent in Korea and health care workers are vulnerable to tuberculosis infection in the hospital. The aims of this study were to develop and validate an education program that teaches senior medical students how to wear and choose the proper size and type of respiratory protective equipment (RPE), which may help reduce the risk of contracting Mycobacterium tuberculosis (MTB) from patients. Overall, 50 senior medical students participated in this education program. Methods of choosing the proper type of RPE, performing a fit check of the RPE, and choosing a suitable mask size were taught by certified instructors using the real-time quantitative fit test (QNFT). The validity of education program was evaluated with qualitative fit test (QLFT) before and after the education as pass or fail. The education program was effective, as shown by the significantly pass rate (increased 30 to 74%) in the QLFT after the education program (p<0.05). Among study participants, changing mask size from medium to small significantly increased the pass rate (p<0.001). Incorporation of this program into the medical school curriculum may help reduce risk of MTB infection in medical students working in the hospital.

Assessing real-time performances of N95 respirators for health care workers by simulated workplace protection factors.

To assess performances of N95 respirators for Health Care Workers (HCWs) in a simulated health-care setting, we measured the Simulated Workplace Protection Factors (SWPFs) in real-time from the volunteers. A total of 49 study subjects, wearing 3 M respirator Model N95 1860 and 1860S, were fit tested using the OSHA Exercise Regimen. The test subjects were asked to perform simulated scenarios, including patient assessments, suction, and intravenous injection (IV) treatment. Two TSI PortaCount instruments continuously measured concentrations in the respirator and the room concentration. For Quantitative Fit Testing (QNFT), 36 out of 49 (73.5%) passed the fit factor (FF) criteria set at 100 and 13 (26.5%) failed. The results of QNFT were found to have a low correlation with SWPF, with R(2)=0.32. The geometric means (GM) and geometric standard deviations (GSD) of SWPF were 68.8 (1.1) for those subjects who passed and 39.6 (1.3) for those who failed. Real-time assessments of SWPF showed that lower SWPFs were; moving head up and down, and bending at the waist. This study identifies the needs for providing different sizes of respirators for HCWs and the importance of performing fit tests for HCWs regularly. And particular movements were identified as attributing factors affecting more on SWPFs.