Off-state gate current with quasi-zero temperature coefficient in n-MOSFETs with reoxidized nitrided oxide as gate dielectric

Temperature stability of off-state gate current (I_g) for n-MOSFET's with reoxidized nitrided oxide (RNO) as gate dielectrics prepared by rapid thermal processing is investigated. A significant phenomeon that I_g remains almost unchanged at elevated temperature is observed. This could be attributed to the fact that reoxidation recovers part of the nitridation-induced lowering of barrier height for hole emission at the RNO/Si interface, resulting in the increases of the hot-hole injection which nearly compensate the decrease of hole generation at elevated temperature in the avalanche regime. The finding reveals a useful behavior with temperature-insensitive off-state gate current for RNO devices requiring a thermally stable operation.     

Isolation of Porphyromonas gingivalis and detection of immunoglobulin A specific to fimbrial antigen in gingival crevicular fluid

The present study evaluated the prevalence of Porphyromonas gingivalis and the correlation between the bacterial culture method and the detection of immunoglobulin A (IgA) specific to the P. gingivalis fimbrial antigen in gingival crevicular fluid (GCF). P. gingivalis was isolated from 78.3% of subgingival plaque samples obtained from active sites and 34.7% of those from inactive sites of periodontal patients. P. gingivalis was isolated from only 4.7% of healthy subjects (control group). Immunoglobulins specific to the P. gingivalis fimbrial antigen were detected by enzyme-linked immunosorbent assay (ELISA). The overall agreement between the results of the P. gingivalis culture method and the results of specific IgA detection in periodontal patients was 71.7% for active sites and 58.7% for inactive sites. IgA specific to P. gingivalis was absent in GCF from all of the sites of healthy subjects. The results suggest that P. gingivalis is associated with the local production of specific IgA. The detection of IgA antibodies specific to P. gingivalis in GCF by ELISA may be used as a predictive parameter to reveal the early phase of the activation of recurrent periodontal infections.     

Effects of three trans isomers of eicosapentaenoic acid on rat platelet aggregation and arachidonic acid metabolism

PURPOSE: To compare in a randomized, prospective manner infectious complication rates associated with presacral drainage versus no drainage in the presence of penetrating rectal injury. METHODS: During a 45-month period, 48 patients with penetrating rectal injuries were entered into a randomized, prospective study at an urban Level I trauma center. The patients were randomized to a presacral drainage group or a nondrainage group. Randomization was performed after detection of the rectal injury. Forty-four injuries were identified by proctoscopy (92%), with the rest detected intraoperatively or by physical examination. All patients with rectal injuries were included regardless of age, associated injuries, time from injury to operation, blood loss, severity of rectal injury, other abdominal organs injured, or hemodynamic stability. Rectal injuries were defined as those injuries to the large bowel distal to the peritoneal reflection. All rectal injuries underwent fecal diversion, and all drainage was accomplished using closed Jackson-Pratt drainage. RESULTS: Forty-eight patients were studied, of whom 25 were randomized to no drainage and 23 were randomized to presacral drainage. The average age for the nondrainage group was 21.9 years, and the average age for the presacral drainage group 26.0 years. The average Penetrating Abdominal Trauma Index score was 34.3 for the nondrainage group and 32.4 for the presacral drainage group. There were two (8%) septic complications (one perirectal and one perivesical abscess) associated with the rectal injuries in the presacral drainage group. The abscesses in the drainage group resolved after computed tomography-guided drainage. There was one (4%) septic complication (rectocutaneous fistula) in the nondrainage group, which was associated with a retained missile fragment. The fistula resolved after bedside percutaneous removal of the missile fragment. CONCLUSION: We conclude that presacral drainage for penetrating rectal injuries has no effect on infectious complications associated with the rectal injuries.     

Modulation of calcium by inhibitory systems in the developing auditory midbrain

Inhibitory synaptic transmission is of fundamental importance during the maturation of central auditory circuits, and their subsequent ability to process acoustic information. The present study investigated the manner in which inhibitory transmission regulates intracellular free calcium levels in the gerbil inferior colliculus using a brain slice preparation. Inhibitory and excitatory postsynaptic potentials were evoked by electrical stimulation of the ascending afferents at the level of the dorsal nucleus of the lateral lemniscus. Pharmacologically isolated inhibitory synaptic potentials were able to attenuate a calcium rise in collicular neurons that was generated by depolarizing current injection. In addition, GABA(A) and glycine receptor antagonists typically led to an increase of calcium in collicular neurons during electrical stimulation of the ascending afferent pathway at the level of the dorsal nucleus of the lateral lemniscus. Bath application of GABA or muscimol, a GABA(A) receptor agonist, evoked a brief hyperpolarization followed by a long-lasting depolarization in inferior colliculus neurons. This treatment also induced a transient calcium increase that correlated with the membrane depolarization phase. Baclofen, a GABA(B) receptor agonist, had no effect on either membrane potential or calcium levels. Ratiometric measures indicated that the muscimol-evoked rise in calcium was approximately 150 nM above basal levels. The muscimol-evoked responses were completely antagonized by bicuculline and attenuated by picrotoxin. Together, these results suggest that inhibitory synaptic transmission participates in the regulation of postsynaptic calcium during the developmental period. Inhibitory transmission may attenuate a calcium influx that is evoked by excitatory synapses, but it can also produce a modest influx of calcium when activated alone. These mechanisms may help to explain the influence of inhibitory transmission on the development of postsynaptic properties.     

A new mixed-mode sustain method to improve the luminous efficiencyof alternating current plasma display panels

In this paper, a new mixed-mode sustain method to improve the luminous efficiency of alternating current plasma display panels is proposed. An opposite discharge is initiated between successive surface sustain discharges during the sustain period. The opposite discharge not only has a higher ultraviolet photon collection factor, but also improves the surface sustain discharge efficiency for the production of ultraviolet photons. The experimental results show that a 21~59% improvement in luminous efficiency within a sustain voltage range of 170 V to 190 V is achieved by the new mixed-mode sustain driving approach, as compared with the conventional surface-type sustain method     

Packaging a fiber Bragg grating without preloading in a simpleathermal bimaterial device

This study presents two athermal packages for compensating for the temperature deviations in an optical fiber Bragg grating (FBG). Usually, a pre-loading mechanism is necessary in packaging the FBG on bimaterial devices. However, through a unique bonding process design, the pre-loading mechanism in the packaging could be eliminated. During the manufacturing processes, AB thermally cured adhesive is used to affix the FBG to the device under a thermal state. In this way, the FBG affixed to the devices is under tension when the temperature drops to room temperature. The devices can also be placed continuously under a thermal state after a thermal curing process for a pre-determined period of time to perform annealing on the FBG, and thereby, further simplifying the manufacturing process. As a result, the total variation in the Bragg wavelength over the range from -40 to +80°C was around 0.1 nm in the two proposed athermal packages     

A comparative analysis of low-power low-voltage dual-edge-triggered flip-flops

This paper compares four previously published static dual-edge-triggered flip-flops (DETFFs) with a proposed design for their performance, power dissipation, and low-voltage low-power applications. For each DETFF, the optimal delay, power consumption, and power-delay product are determined as the primary figures of merit. The proposed design is shown to have the least energy at low voltages.     

A dual-antenna phase-array ultra-wideband CMOS transceiver

Ultra-wideband (UWB) systems use high-bandwidth signals to enable a new generation of ultra-high-data-rate wireless applications. Implementation of a high-bandwidth RF system in the 3-5 GHz band presents challenges that can be solved by circuit and system techniques. This article looks at the motivation and requirements for a WiMedia-compliant UWB system implemented for a target application in wireless video transmission. It explores the circuit-level trade-offs in CMOS radio and some of the system-level methods, such as selection diversity and equal-gain combining, used to increase robustness in multipath and interference environments. The radio (S. Lo, 2006) is part of a two-chip solution that includes a digital baseband chip that implements the WiMedia-compliant PHY and MAC. The measured results of the 0.18 /spl mu/m CMOS UWB transceiver demonstrate the efficacy of these techniques in the final RF and system performance.     

Image watermarking using tree-based spatial-frequency feature of wavelet transform

In this paper, an image watermarking scheme is developed using the tree-based spatial-frequency feature of wavelet transform. With our approach, the watermark sequence is inserted in those high activity texture regions of an image having the maximum strength of just noticeable distortion (JND) tolerance of the human visual system (HVS). Simulation results show that the proposed method achieves a good compromise between the robustness and transparency.