Letter to the Editor: Performance Analysis of the Aptima HBV Quant Assay for Hepatitis B virus DNA Quantification in Plasma.

The quantification of hepatitis B virus (HBV) DNA is critical for the diagnosis and management of HBV infections. We evaluated the performance of the Aptima HBV Quant assay for quantitative HBV DNA analysis. The intra-assay coefficient of variation for this assay was 2.08% (mean 3.45 log IU/mL) and 1.10% (mean 5.23 log IU/mL). Linearity ranged from 1.03 to 8.20 log IU/mL. The limit of detection was estimated at 4.31 IU/mL, which corresponded to the 4.29 IU/mL claimed by the manufacturer. All 25 other viral infections were determined to be negative. Passing-Bablok regression analysis showed no significant deviations between Aptima HBV Quant assay and Abbott RealTime HBV assay. The Aptima HBV Quant assay demonstrated comparable performance to the Abbott assay.

Rapid Defrost Transparent Thin-Film Heater with Flexibility and Chemical Stability.

Zn-doped SnOx/Ag/Zn-doped SnOx(ZTO/Ag/ZTO) multilayer thin films fabricated on a polyethylene terephthalate (PET) substrate using an optimized N2-to-(Ar + O2) gas ratio are used for transparent thin-film heaters with high performance and chemical stability. The ZTO/Ag/ZTO-based multilayer thin film exhibits enhanced durability at high temperatures and humid environments by incorporating nitrogen. The bending test results-there was no significant change in the sheet resistance even after 10,000 bending cycles-highlight the mechanical flexibility of the ZTO/Ag/ZTO multilayer thin film. The ZTO/Ag/ZTO-based thin-film heater on PET, fabricated under optimized deposition gas conditions, exhibits a fast thermal response time of 30 s and a low driving voltage of 6 V to attain 100 °C. It also exhibits uniform heat distribution at saturated temperature and chemical stability after 100 heating-cooling cycles. Hence, the proposed ZTO/Ag/ZTO-based thin-film heater is applicable for use in front and rear window automobile and building applications.

Failed anterior lumbar interbody fusion due to incomplete foraminal decompression.

BACKGROUND: Anterior lumbar interbody fusion (ALIF) has gained widespread popularity for spinal disorders requiring fusion. The purpose of this study was to analyze ALIF failures. METHODS: The medical records of 223 patients treated with ALIF between January 2007 and June 2008 were retrospectively reviewed. Patients with unfavorable outcomes, including subsequent posterior decompression at the index level or poor outcomes after ALIF were identified based on clinical and radiological findings. The patients were divided into two groups: an unfavorable group and a favorable group. Preoperative clinical and radiological factors for each group were statistically analyzed. RESULTS: Two hundred of the 223 patients were enrolled in this study. Thirteen (6.5%) of 200 patients resulted in unfavorable outcome. Four patients (2%) of them underwent posterior decompressive surgery. The main cause of unfavorable outcomes was incomplete decompression of the foraminal stenosis. Unfavorable outcomes were obtained in patients with the level of L5-S1 (p = 0.036), higher body mass index (p = 0.048), higher percentage of slippage (p = 0.024), and severe facet arthropathy (p = 0.013). However, there was no difference in preoperative disc height, foraminal size, facet angle, facet tropism, or preoperative visual analog scale for back and leg pain, the Oswestry disability index, symptom duration, and fusion rate between the two groups. CONCLUSION: Based on these results, posterior decompression and fusion may be considered for obese patients with the level of L5-S1, high-grade spondylolisthesis, or severe facet arthropathy. On the other hand, ALIF can be used an effective alternative treatment in many spinal disorders requiring fusion.

Proton-conductive nanochannel membrane for fuel-cell applications.

Novel design of proton conductive membrane for direct methanol fuel cells is based on proton conductivity of nanochannels, which is acquired due to the electric double layer overlap. Proton conductivity and methanol permeability of an array of nanochannels were studied. Anodic aluminum oxide with pore diameter of 20 nm was used as nanochannel matrix. Channel surfaces of an AAO template were functionalized with sulfonic groups to increase proton conductivity of nanochannels. This was done in two steps; at first -SH groups were attached to walls of nanochannels using (3-Mercaptopropyl)-trimethyloxysilane and then they were converted to -SO3H groups using hydrogen peroxide. Treatment steps were analyzed by Fourier Transform Infrared spectroscopy and X-ray Photoelectron Spectroscopy. Proton conductivity and methanol permeability were measured. The data show methanol permeability of membrane to be an order of magnitude lower, than that measured of Nafion. Ion conductivity of functionalized AAO membrane was measured by an impedance analyzer at frequencies ranging from 1 Hz to 100 kHz and voltage 50 mV to be 0.15 Scm(-1). Measured ion conductivity of Nafion membrane was 0.05 Scm(-1). Obtained data show better results in comparison with commonly used commercial available proton conductive membrane Nafion, thus making nanochannel membrane very promising for use in fuel cell applications.

Rapid cell-deformability sensing system based on slit-flow laser diffractometry with decreasing pressure differential.

A slit-flow apparatus with a laser-diffraction method has been developed with significant advances in ektacytometry design, operation and data analysis. In the slit-flow ektacytometry, the deformation of red blood cells subjected to continuously decreasing shear stress in slit-flow can be quickly measured with adopting a laser-diffraction technique. Both the laser-diffraction image and pressure were measured with respect to time, which enable to determine the elongation index (EI) and the shear stress. The range of shear stress is 0-35 Pa and the measuring time is < 2 min. The EI is determined from an isointensity curve in the diffraction pattern using an ellipse-fitting program. The present study proposed the deformability index (DI) as a new measure of the RBC deformability, which is defined as an integral area under the EI curve between 0 and tau10 (tau(w) = 0-10). The key advantage of this design is the incorporation of a disposable element that holds the blood sample, which enables the present system to be easily used in a clinical setting.