Circuits and AMOLED display with self‐aligned a‐IGZO TFTs on polyimide foil

A process to make self‐aligned top‐gate amorphous indium‐gallium‐zinc‐oxide (a‐IGZO) thin‐film transistors (TFTs) on polyimide foil is presented. The source/drain (S/D) region's parasitic resistance reduced during the SiN interlayer deposition step. The sheet resistivity of S/D region after exposure to SiN interlayer deposition decreased to 1.5 kΩ/□. TFTs show field‐effect mobility of 12.0 cm²/(V.s), sub‐threshold slope of 0.5 V/decade, and current ratio (I_ON/OFF) of >10⁷. The threshold voltage shifts of the TFTs were 0.5 V in positive (+1.0 MV/cm) bias direction and 1.5 V in negative (?1.0 MV/cm) bias direction after extended stressing time of 10⁴ s. We achieve a stage‐delay of ~19.6 ns at V_DD = 20 V measured in a 41‐stage ring oscillator. A top‐emitting quarter‐quarter‐video‐graphics‐array active‐matrix organic light‐emitting diode display with 85 ppi (pixels per inch) resolution has been realized using only five lithographic mask steps. For operation at 6 V supply voltage (V_DD), the brightness of the display exceeds 150 cd/m².     

Assessment of the ability of five culture media for the detection of Escherichia coli O157

Cattle are a common reservoir for Escherichia coli O157:H7. Prior to confirming its presence in a sample, proper isolation of E. coli O157 is necessary. Consequently, this study evaluated the ability of five commercial plating media to isolate E. coli O157 from 138 samples of fresh cattle faeces, water from water trough and pond, and surfaces of water trough and hay bunk. For the isolation of E. coli O157, samples were enriched in tryptic soya broth, followed by immunoseparation and then plating on SMAC, CT‐SMAC, CHROMagar^? O157, Tellurite CHROMagar^? O157 and Vancomycin Cefixime Cefsoludin CHROMagar^? O157. Real‐time PCR targeting genes stx₁, stx₂ and wzy_O157 was used to confirm selected isolates. When analysed together, CT‐SMAC and CHROMagar^? O157 were the best combination for isolating E. coli O157, giving 79% true‐positive results and only 0.05% false‐negative results.     

Inhibition of polyamine biosynthesis alters oviposition behavior in female crickets.

The role of polyamines in the expression of cricket oviposition, a juvenile hormone-dependent behavior, was investigated using a specific inhibitor of ornithine decarboxylase, α-difluoromethylornithine (α-DFMO). The fat body of treated female house crickets (Acheta domesticus) did not show any putrescine and presented reduced levels of spermidine, whereas spermine titres were significantly enhanced. In nervous tissue, α-DFMO did not affect spermine titres but induced a severe drop in spermidine levels. In polyamine depleted females, the expression of egg-laying behavior was delayed and was expressed less frequently compared with controls. As drug treatment did not seem to affect juvenile hormone titres, the data suggest that juvenile hormone might act on behavior by way of polyamine metabolism. These results support the view that, in insects, as in vertebrates, the ornithine decarboxylase-polyamine system is involved in the maturation of complex behaviors. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Qualification of parallel kinematics machines in high-speed milling on free form surfaces

Serial milling machines may one day find their limits in high-speed milling due to their limited dynamic characteristics. Indeed, the major drawback of a serial structure is that it consists of a pile of actuated joints; hence the mass on board for the axis underneath can be huge. This is mainly the reason why parallel structures are of interest in milling: in order to go faster.Such structures have been developed since 1980 for robotic tasks, while the first parallel kinematics machine tool appeared only 14 years later. Since then, very few papers have been published that deal with the potential of these structures in milling. The objective of this study is to show the potentialities of parallel structures in milling and especially in high-speed milling of free form surfaces, in comparison to serial structures. To do so, experiments have been realised on four serial kinematics machines (SKMs) and four parallel kinematics machines (PKMs). These experiments were of two kinds: either a real piece has been milled, or the output axis encoder data have been saved (this method of measurement has been previously developed in our team).So far, a comparison between the two structures (serial and parallel) has been possible, which permitted us to show that PKMs can provide interesting results in terms of time and precision. Hence, the goal of this study has been reached, as the PKMs potentialities in milling free form surfaces have been highlighted. With more experiments, a generalisation, by taking into account all the parameters (shape and material of the part, structure of the machine, etc.), will be attempted. In parallel, the development of our simulator for PKMs is necessary in order to be able to predict milling on these machines.     

Influence of the load modelling during gait on the stress distribution in a femoral implant

Introduction

When designing and installing implants, stress analyses should be performed in conditions close to those of everyday use. Specifically, for femoral implants, cyclic loading during gait has been demonstrated to produce fatigue failure. However, there is still no consensus in the literature regarding which modelling procedure is the most appropriate to simulate implant working conditions. This work proposes a method for realistic load modelling of the human body during gait based on flexible multibody dynamics.

Method

The proposed dynamic method was applied to a case study of a lower limb implant that failed by fatigue. The computed stresses were compared to the stresses obtained using the other three methods found in the literature, which are principally based on static or quasi-static load modelling.

Results

For all compared methods, the maximum computed stress was located in the same region of the implant. The maximum stress provided using flexible multibody dynamics was equal to 346 MPa, which was 355% greater than the maximum value given by the static method and 18% greater than the value given by the quasi-static method.

Discussion and conclusion

The proposed dynamic method was in agreement with the conclusions of the previous failure analysis performed on the broken implant. Conversely, the static and quasi-static methods were not representative of the real loading conditions induced by gait. Moreover, the dynamic method emphasizes the pertinence of evaluating the fluctuations in the critical stress during the gait cycle, which is mandatory when studying fatigue failures.

     

Forced‐ and Self‐Rotation of Magnetic Nanorods Assembly at the Cell Membrane: A Biomagnetic Torsion Pendulum

In order to provide insight into how anisotropic nano‐objects interact with living cell membranes, and possibly self‐assemble, magnetic nanorods with an average size of around 100 nm × 1 µm are designed by assembling iron oxide nanocubes within a polymeric matrix under a magnetic field. The nano–bio interface at the cell membrane under the influence of a rotating magnetic field is then explored. A complex structuration of the nanorods intertwined with the membranes is observed. Unexpectedly, after a magnetic rotating stimulation, the resulting macrorods are able to rotate freely for multiple rotations, revealing the creation of a biomagnetic torsion pendulum.