Interpretation time of serial chest CT examinations with stacked-metaphor workstation versus film alternator

PURPOSE: Interpretation time of serial staging chest CT cases, which each contained current and previous examinations, with a simple prototype workstation called filmstack was experimentally compared with interpretation time with a film alternator. MATERIALS AND METHODS: The filmstack displayed a "stack" of sections for each examination; user controls allowed rapid selection of preset attenuation windows and both synchronized and unsynchronized scrolling. Eight radiologists were timed as they used the filmstack and the film alternator to interpret four ergonomically complex serial CT cases. RESULTS: All reports dictated on the basis of findings with filmstack and film were of acceptable clinical accuracy. The time to examine a case with filmstack was significantly faster than the time with film, including the time to load and unload the alternator (99% confidence [P = .01]). There was no statistically significant difference in interpretation time between filmstack and prehung film. CONCLUSION: Use of a low-cost stacked CT workstation with a single 1,024 x 1,024 monitor is an effective means of interpreting cases that require comparison of multiple CT examinations.     

Nickel oxide thin films by spray pyrolysis

The preparative parameters have been optimized for NiO film formation in fabricated Spray Pyrolysis System using pneumatic air pressure driven aerosol formation. The structural studies by X-ray diffractometer (XRD) have been carried out to investigate crystallographic features. It was revealed that NiO crystallizes in cubic bunsenite structure. The optical band gap for direct transitions was found to be equal to 3.67 eV. Field Emission Scanning Electron Micrographs (FESEM) have been employed to study morphological aspects of the prepared films. The elemental depth profiles of film contents have been obtained Auger Electron Spectroscopic (AES) studies.     

The mismatch negativity to frequency deviant stimuli during natural sleep

Eight subjects spent a single night in the sleep laboratory. Event-related potentials (ERPs) were recorded during the presentation of two auditory "oddball' stimulus conditions in which tonal frequency was manipulated. In the first condition, 1000 Hz "standard' and 2000 Hz "deviant' tones were presented. In the second condition, the deviant tone was reduced to 1050 Hz. In both conditions, deviant probability was 0.2. Stimuli were presented every 600 ms during wakefulness and stages 2, 4, and REM of sleep. A distinctive N1 wave was visible in both stimulus conditions when the subject was awake. The deviant stimuli elicited a "mismatch negativity' (MMN) that inverted in polarity at the mastoid. In REM sleep, an N1 and a MMN were also elicited in both conditions. In the large deviance condition, the MMN had a slightly attenuated amplitude and was shorter in duration while in the small deviant condition, its peak latency was unusually early. Neither the N1 nor the MMN could be recorded in non-REM sleep.     

Unreinforced Masonry Walls: Nonlinear Finite Element Analysis with a Unified Constitutive Model

This paper presents a unified model for characterizing the behavior of masonry structures. The model is based on the Disturbed State Concept (DSC) with modified hierarchical single yield surface (HISS) plasticity, which is called DSC/HISS-CT and which is used to simulate the behavior of masonry structures. The model uses two HISS yield surfaces for compressive and tensile behavior. The proposed constitutive model is verified by comparing numerical predictions with results available from test data; the comparisons are found to be highly satisfactory. A new explicit formula is also presented to estimate the strength of unreinforced masonry structures.     

A unified and flexible solution for integrating CRL and OCSP into PKI applications

Public key certificates (PKCs) are used nowadays in several security protocols and applications, so as to secure data exchange via transport layer security channels, or to protect data at the application level by means of digital signatures. However, many security applications often fail to manage properly the PKCs, in particular when checking their validity status. These failures are partly due to the lack of experience (or training) of the users who configure these applications or protocols, and partly due to the scarce support offered by some common cryptographic libraries to the application developers. This paper describes the design and implementation of a light middleware dealing with certificate validation in a unified way. Our middleware exploits on one side the libraries that have already been defined or implemented for certificate validation, and it constructs a thin layer, which provides flexibility and security features to the upper layer applications. In our current approach, this layer boasts an integrated approach to support various certificate revocation mechanisms, it protects the applications from some common security attacks, and offers several configuration and performance options to the programmers and to the end users. We describe the architecture of this approach as well as its practical implementation in the form of a library based on the famous OpenSSL security library, and that can be easily integrated with other certificate‐aware security applications. Copyright © 2009 John Wiley & Sons, Ltd.     

Predictability of healing of ischemic leg ulcers by radioisotopic and Doppler ultrasonic examination

In a prospective study of twenty-six patients with ischemic ulcerations of the lower extremity, the predictive reliability with regard to spontaneous wound healing of diabetes, pedal pulses, ankle blood pressure (ABP) as measured by doppler ultrasound, and "leg ulcer scan" as performed by the intra-arterial injection of radioactive albumin was evaluated. The results suggest that only the leg ulcer scan is significantly reliable in predicting the likelihood of spontaneous healing. The following format for the evaluation of the ischemic leg ulcer is therefore suggested: (1) If pedal pulses are present, a three week trial of conservative therapy is indicated before further evaluation. (2) If the doppler ABP is 50 mm Hg or less, the ulcer will not heal spontaneously. (3) Leg ulcer scan is indicated: (a) in the absence of pedal pulses if ABP is less than 50 mm Hg; (b) in the presence of pedal pulses if there is no evidence of spontaneous healing after three weeks of conservative therapy.     

Microhardness studies of SnI2 and SnI4 single crystals

The variation in the microhardness of tin-di-iodide (SnI₂) and tin-tetra-iodide (SnI₄) crystals has been determined using Vicker’s microhardness indentor. It is observed that the microhardness of the crystals depends on the applied load and is independent of the duration of loading. Vickers Hardness Numerals (vhn) for SnI₂ is found to be greater than that of SnI₄ crystals. Mayer’s equation and implications have been discussed.     

Remote sensing of canopy light use efficiency in temperate and boreal forests of North America using MODIS imagery

Light use efficiency (LUE) is an important variable characterizing plant eco-physiological functions and refers to the efficiency at which absorbed solar radiation is converted into photosynthates. The estimation of LUE at regional to global scales would be a significant advantage for global carbon cycle research. Traditional methods for canopy level LUE determination require meteorological inputs which cannot be easily obtained by remote sensing. Here we propose a new algorithm that incorporates the enhanced vegetation index (EVI) and a modified form of land surface temperature (T_m) for the estimation of monthly forest LUE based on Moderate Resolution Imaging Spectroradiometer (MODIS) imagery. Results demonstrate that a model based on EVI × T_m parameterized from ten forest sites can provide reasonable estimates of monthly LUE for temperate and boreal forest ecosystems in North America with an R² of 0.51 (p < 0.001) for the overall dataset. The regression coefficients (a, b) of the LUE–EVI × T_m correlation for these ten sites have been found to be closely correlated with the average EVI (EVI_ave, R² = 0.68, p = 0.003) and the minimum land surface temperature (LST_min, R² = 0.81, p = 0.009), providing a possible approach for model calibration. The calibrated model shows comparably good estimates of LUE for another ten independent forest ecosystems with an overall root mean square error (RMSE) of 0.055 g C per mol photosynthetically active radiation. These results are especially important for the evergreen species due to their limited variability in canopy greenness. The usefulness of this new LUE algorithm is further validated for the estimation of gross primary production (GPP) at these sites with an RMSE of 37.6 g C m^? 2 month^? 1 for all observations, which reflects a 28% improvement over the standard MODIS GPP products. These analyses should be helpful in the further development of ecosystem remote sensing methods and improving our understanding of the responses of various ecosystems to climate change.     

Optical sensing of biomolecules using microring resonators

A biosensor application of vertically coupled glass microring resonators with Q/spl sim/12 000 is introduced. Using balanced photodetection, very high signal to noise ratios, and thus high sensitivity to refractive index changes (limit of detection of 1.8/spl times/10/sup -5/ refractive index units), are achieved. Ellipsometry and X-ray photoelectron spectroscopy results indicate successful modification of biosensor surfaces. Experimental data obtained separately for a bulk change of refractive index of the medium and for avidin-biotin binding on the ring surface are reported. Excellent repeatability and close-to-complete surface regeneration after binding are experimentally demonstrated.