Phosphorylcholine-containing lipid molecular species profiling in biological tissue using a fast HPLC/QqQ-MS method

A fast reversed-phase liquid chromatography-electrospray ionization triple quadrupole mass spectrometry method was developed for the molecular species profiling of glycerophosphocholine (GPC) and sphingomyelin (SM) in total lipid extracts. A two-stage mass spectrometry strategy was adopted to analyze in detail the composition of lipid molecular species. Precursor ion analysis was first conducted to obtain the preliminary composition profile of the phosphorylcholine-containing lipid. The product ion spectra were sequentially acquired for each recorded signal to determine the molecular structure of the lipid. A total of 150 GPCs and 12 SMs were identified in the fetal mouse lung with relative amounts ranging from 13.7?% to less than 0.002?% (normalizing by the total signal response). A column packed with core–shell particles was used to obtain excellent chromatographic separation with a shorter time demand in a conventional high-performance liquid chromatography system. Considering the compromise between the chromatographic efficiency and the electrospray signal response, the optimization of the mobile phase improves the chromatographic plate number to approximately 40,000 and the detection limits to less than 0.001?mg/L. The applicability of the method was validated through a study of chemically induced early lung maturation. The metabolic alteration in the fetal mouse lung was clearly reflected in the GPC and SM composition with several characteristics of the molecular structure that related to the character of the phospholipid layer upon the epithelial lining of alveoli and the relevant cell function. The results indicated that this analytical strategy is reliable for comprehensive molecular species profiling of GPC and SM and might be extended to the analysis of other phospholipids.

Improvement in the thermal conductivity of aluminum substrate for the desktop PC Central Processing Unit (CPU) by the Taguchi method

This paper examines the thermal conductivity of thin films (Cu or Ag) deposited on 1050 aluminum alloy substrates (99.57% purity) by various sputtering. The Taguchi method was used to clarify the influence of various deposition conditions (target, sputtering method, power, deposition time and annealing temperature). This paper employs the signal-to-noise (S/N) ratio and analysis of variance (ANOVA) to study the coating operation performance. The experimental results point out the optimum conditions of highly thermal conduction were the Ag target, sputtering method of RF, power of 300 W, deposition time of 15 min, and no annealing temperature. The sputtering method and power are the most significant factors among the five controllable factors affecting the thermal conductivity of aluminum substrate in the sputtering process.     

Influences of Plasma Treatment and 60Co γ-Ray Radiation on the Over-Voltage Positive Temperature Coefficient of High Density Polyethylene/Carbon Black Nano Composites

Argon plasma-pretreated high-density polyethylene (PHDPE) was blended with the conductive nano carbon black (CB) and inorganic flame retardant (magnesium hydroxide, Mg(OH)₂) was added. Influences of the CB content, plasma treatment time, plasma treatment power, and dosage of ⁶⁰Co γ-ray radiation on positive temperature coefficient (PTC) behaviors of composite were studied. In addition, the over-voltage resistance behavior of the composites was also investigated. The free radical of PHDPE was measured by 1,1-diphenyl-2-picryhydrazyl (DPPH) method. The gel contents of composite were measured by solvent extraction method. The results showed that the room-temperature volume resistivity and PTC effect of composite were improved significantly with plasma treatment. The PHDPE composite with ⁶⁰Co γ-ray radiation eliminated the negative temperature coefficient (NTC) effect in the composites effectively, and the PTC intensity of composite was increased. With increasing of radiation dosage from 20 Mrads to 80 Mrads, the gel content of composites increased up to 83.84% and the response temperature of composites shifted to low temperature (127.5 °C to 114.8 °C). In this work, the composites also successfully passed the over-voltage resistance test, and possessed good reproducibility.     

Simplified Formula of Bending Loss for Optical Fiber Sensors

A simple fiber-optic bending loss formula is achieved for optical fiber sensors. This simple formula considers various bending radii, number of turns, extra bending angle, and wavelength and has good agreement with theoretical and experimental data. We also propose a simplified formula for sensitivity of the fiber-optic bending loss in this article. The defined sensitivity formula has the benefit of showing parameters for fiber-optic bending sensor systems.     

Structural dependence of electrical properties of Ge films prepared by RF magnetron sputtering

This paper investigates the electrical properties of non-hydrogenated and hydrogenated germanium thin films deposited on silicon nitride coated glass in order to develop a material for the bottom cells of low cost monolithic tandem solar cells. Films were deposited by RF magnetron sputtering over a series of substrate temperatures up to 500°C. A structure-dependent conduction property of germanium films was found. As the substrate temperature increased from 255 to 400°C, both series of films first showed n-type conductivity with progressively increasing room-temperature dark resistivity that peaks around the type switch. Upon attaining p-type character the resistivity decreased rapidly with further increase in T _s. Accompanying these trends, the film grain orientation evolved from predominantly (220) to (111).     

Expression of the neuroprotective slow Wallerian degeneration (Wld S ) gene in non-neuronal tissues

Background  

The slow Wallerian Degeneration (Wld ^S ) gene specifically protects axonal and synaptic compartments of neurons from a wide variety of degeneration-inducing stimuli, including; traumatic injury, Parkinson's disease, demyelinating neuropathies, some forms of motor neuron disease and global cerebral ischemia. The Wld ^S gene encodes a novel Ube4b-Nmnat1 chimeric protein (Wld^S protein) that is responsible for conferring the neuroprotective phenotype. How the chimeric Wld^S protein confers neuroprotection remains controversial, but several studies have shown that expression in neurons in vivo and in vitro modifies key cellular pathways, including; NAD biosynthesis, ubiquitination, the mitochondrial proteome, cell cycle status and cell stress. Whether similar changes are induced in non-neuronal tissue and organs at a basal level in vivo remains to be determined. This may be of particular importance for the development and application of neuroprotective therapeutic strategies based around Wld ^S -mediated pathways designed for use in human patients.