Effect of diamond-like carbon coating on the emissioncharacteristics of molybdenum field emitter arrays

We have studied the electron emission characteristics of Mo field emitter arrays (FEAs) using a diamond-like carbon (DLC) film deposited by a layer-by-layer technique using plasma enhanced chemical vapor deposition. The turn-on voltage was lowered from 55 to 30 V by a 20 nm thick hydrogen-free DLC coating and maximum emission current was increased from 166 to 831 μA. Also the gate voltage required to get the anode current of 0.1 (μA/emitter) decreases from 77 to 48 V. Furthermore, the emission current from DLC coated Mo FEAs is more stable than that of noncoated Mo FEAs     

Study on the water flooding in the cathode of direct methanol fuel cells

Water flooding phenomena in the cathode of direct methanol fuel cells were analyzed by using electrochemical impedance spectroscopy. Two kinds of commercial gas diffusion layers with different PTFE contents of 5 wt% (GDL A5) and 20 wt% (GDL B20) were used to investigate the water flooding under various operating conditions. Water flooding was divided into two types: catalyst flooding and backing flooding. The cathode impedance spectra of each gas diffusion layer was obtained and compared under the same conditions. The diameter of the capacitive semicircle became larger with increasing current density for both, and this increase was greater for GDL B20 than GDL A5. Catalyst flooding is dominant and backing flooding is negligible when the air flow rate is high and current density is low. An equivalent model was suggested and fitted to the experimental data. Parameters for catalyst flooding and backing flooding were individually obtained. The capacitance of the catalyst layer decreases as the air flow rate decreases when the catalyst flooding is dominant.     

Quantum dot-based screening system for discovery of g protein-coupled receptor agonists

Cellular imaging has emerged as an important tool to unravel biological complexity and to accelerate the drug-discovery process, including cell-based screening, target identification, and mechanism of action studies. Recently, semiconductor nanoparticles known as quantum dots (QDs) have attracted great interest in cellular imaging applications due to their unique photophysical properties such as size, tunable optical property, multiplexing capability, and photostability. Herein, we show that QDs can also be applied to assay development and eventually to high-throughput/content screening (HTS/HCS) for drug discovery. We have synthesized QDs modified with PEG and primary antibodies to be used as fluorescent probes for a cell-based HTS system. The G protein-coupled receptor (GPCR) family is known to be involved in most major diseases. We therefore constructed human osteosarcoma (U2OS) cells that specifically overexpress two types of differently tagged GPCRs: influenza hemagglutinin (HA) peptide-tagged κ-opioid receptors (κ-ORs) and GFP-tagged A3 adenosine receptors (A3AR). In this study, we have demonstrated that 1) anti-HA antibody-conjugated QDs could specifically label HA-tagged κ-ORs, 2) subsequent treatment of QD-tagged GPCR agonists allowed agonist-induced translocation to be monitored in real time, 3) excellent emission spectral properties of QD permitted the simultaneous detection of two GPCRs in one cell, and 4) the robust imaging capabilities of the QD-antibody conjugates could lead to reproducible quantitative data from high-content cellular images. These results suggest that the present QD-based GPCR inhibitor screening system can be a promising platform for further drug screening applications.     

The effects of nephrectomy on the developing fetus

Bilateral renal pathologies such as renal agenesis and renal dysplasia and lower urinary tract obstruction have been reported to result in pulmonary hypoplasia. Although oligohydramnios and resultant thoracic compression was suggested to be the cause of pulmonary hypoplasia, the exact mechanism is still unknown. Additionally the effect of absence of renal tissue on the development of the fetus has not been previously studied in detail. Therefore an experimental study was planned to investigate the effects of fetal nephrectomy on development. The fetuses from 27 New Zealand white rabbits were studied on the 23rd day of gestation. Right ovarian-end fetuses underwent bilateral nephrectomy or sham operations. Rabbits underwent hysterectomy on gestational day 30, and live fetuses were studied. Fetal body, lung, heart and liver weights, and lung, heart and thorax volumes were determined, organ weight/body weight ratios were calculated. Additionally, lungs were evaluated by histological examination. Although fetal nephrectomy resulted in decreased body weight (BW), lung, heart, liver weights and heart weight/BW ratio (p < 0.05), lung weight/BW and liver weight/BW ratios did not differ. Additionally, heart and thorax volumes were significantly decreased in the nephrectomy group (p < 0.05). However lung volume and thorax volume/BW ratio did not differ between groups. The histological evaluation of lungs revealed exfoliated cells but normal lung development. Bilateral fetal nephrectomy results in small-for-gestational age (SGA) status during birth without affecting the development of organic systems. Since SGA status may be associated with decreased placentofetal blood flow, bilateral nephrectomy may act through decreasing placentofetal blood flow and/or through the lack of kidney-related growth factors.     

Umbilical polyp originating from urachal remnants

Umbilical polyp is a rare disorder of the umbilical region in childhood. It is said to be the result of incomplete closure of the omphalomesenteric duct and presents as a red, moist umbilical mass after separation of the umbilical cord. Umbilical polyp originating from the urachus has not previously been reported. A 10-year-old boy with an umbilical polyp related to the urachus is presented to stress the possibility that umbilical polyps can originate not only from the omphalomesenteric duct but also from urachal remnants.     

Importance and measurement of decay rate when assessing nitrification kinetics.

Nitrification kinetics are important for process design, optimization and capacity rating of activated sludge wastewater treatment plants. Assessment of nitrification behaviour historically has focused on measuring the nitrifier maximum specific growth rate, micro(AUT). Very little attention has been directed at the of nitrifier organism rate has been assumed negligible. However, incorrect assessment of decay rate leads to errors in the micro(AUT) estimate; the magnitude of the error depends on the micro(AUT) measurement method employed. This paper illustrates why decay rate is important when measuring micro(AUT), and that the decay rate is significant. The paper also explains why measurement methods for nitrifier decay may have underestimated the decay rate. Results from an experiment incorporating improvements to previously suggested methods and data analysis are presented.     

Investigation into High-Temperature Interfacial Strength of Heat-Resisting Alloy Deposited by Laser Melting Process

Metals and Materials International - This paper presents an investigation of the interfacial strength between a material deposited on a substrate via direct energy deposition (DED) process. Using...