High-speed, low-power BiCMOS comparator using a pMOS variable load

A novel BiCMOS latched comparator for high-speed, low-power applications is proposed. The resistive load of conventional current-steering comparators is replaced by a variable load made by a pMOS transistor that, during the comparison cycle, is successively biased in three different operating regions. This solution provides a lower power consumption than conventional architectures, without sacrificing sampling speed. Post-layout simulation results and measurements performed on the prototypes are presented     

Clinical heterogeneity of adhalin deficiency

STUDY DESIGN: An assessment was made of the efficacy of a combined laminoplasty and foraminotomy operation for patients with coexisting myelopathy and unilateral radiculopathy. The procedure was done in 17 patients. OBJECTIVES: The patients were followed with lateral flexion and extension radiographs, computed tomography scans, and an assessment system specially designed to qualitatively evaluate the patients' neurologic status. Follow-up period averaged 4 years (range, 2.1-9.3 years). SUMMARY OF BACKGROUND DATA: Excellent-to-good results were obtained for 76% (13 of 17) of the patients without any significant functional compromise based on the radiographs. Sixteen nerve roots were decompressed with a less than 25% foraminotomy, whereas eight were decompressed by a 25%-50% foraminotomy without serious neurologic damage, except for one patient. The neurologic results appeared unrelated to the extent of foraminotomy. METHODS: A refined procedure for combined laminoplasty and foraminotomy was reviewed retrospectively in terms of neurologic outcome and radiographic data. RESULTS: The present series is small, and results are not comparable directly with other methods. The procedure appears effective for myelopathy and radiculopathy. This procedure is applicable to patients with myelopathy and coexisting nerve root impingement anterolaterally or in the neural foramen. CONCLUSION: The combined laminoplasty and foraminotomy operation may provide greater neurologic improvement in patients with coexisting myelopathy and unilateral radiculopathy, while maintaining cervical spine stability after surgery.     

Clinical features, treatment and outcome in a series of 93 patients with low-grade gastric MALT lymphoma

The purpose of this paper is to report the clinical characteristics and treatment outcome following different therapeutic approaches in a large series of patients with primary low-grade MALT lymphoma of the stomach. A total of ninety-three patients (median age 63 years) were reviewed. The patients were treated by different modalities (local treatment alone, combined treatment, chemotherapy, antibiotics alone); seven patients refused any treatment. The antibiotic-treated group of patients was prospectively followed with regular endoscopic biopsies, and their responses were histologically evaluated. The 5-years projected overall survival is 82% (95% C.I.; 67%-91%) in the series as a whole. Second tumors were observed in 21.5% of the patients in this series (95% CI 14%v to 31%). There was no apparent difference in overall survival and event-free survival between patients who received different treatments. In the antibiotic-treated group histologic regression of MALT lymphoma was documented in 67% of patients (95% CI 51% to 80%). In conclusion the indolent nature of the disease justifies a conservative approach. The use of antibiotics as first-line therapy may avert or at least postpone the indication for surgical resection in the majority of patients.     

Analysis of distortion in A/D converters by time-domain andcode-density techniques

Two new methods for measuring the total harmonic distortion of an A/D converter are described. One is based on time-domain analysis, the other on modified code density analysis. Experiments show that these methods give results comparable to the ones provided by FFT analysis. It is then shown, by both experiments on a flash converter and computer simulations, that the conventional code density analysis does not provide accurate signal-to-noise-plus-distortion ratio (SNDR) estimates at the highest frequencies, while the proposed methods do     

A new method for estimating the aperture uncertainty of A/Dconverters

Aperture uncertainty measurements are strongly influenced by quantization, converter nonlinearity and test setup noise. The proposed method solves the difficulties arising from quantization, and nonlinearity. The method estimates the noise distribution function by fine adjustment of the input signal offset. The contribution of jitter-induced voltage noise is separated from additive noise in two different ways. Finally, the aperture uncertainty, assumed independent of the frequency, is estimated by varying the signal frequency. Experimental results obtained on 8 and 10 bit converters are discussed     

Corrosion behaviour of a 2219 aluminium alloy treated with a chromate conversion coating exposed to a 3.5% NaCl solution

This study investigates the formation of a chromate conversion coating at Al–Cu–Fe–Mn intermetallic sites of an Al2219 alloy and the corrosion initiation at these sites in a 3.5% NaCl solution, using SEM, AES and EDX. Changes in the surface chemistry were monitored after progressive exposures to the solution up to 42 h. The coating was found to be thinner and more defective on the intermetallic. Initially, Al is dissolved and Al(OH)₃ deposited on and around the intermetallic. After 42 h of exposure, Al(OH)₃, Fe and Mn oxides and small particles of elemental Cu are deposited as corrosion products.     

Automobile proximity and indoor residential concentrations of BTEX and MTBE

Attached garages have been identified as important sources of indoor residential air pollution. However, the literature lacks information on (1) how the proximity of cars to the living area affects indoor concentrations of gasoline-related compounds, such as benzene; and (2) the origin of these pollutants, i.e., vapor or tailpipe emissions. We analyzed data from the Relationships of Indoor, Outdoor, and Personal Air (RIOPA) study to evaluate indoor (C_in) and outdoor (C_out) concentrations for 114 residences with cars either in an attached garage, a detached garage or carport, or without cars. Results indicate that single-family detached homes with cars in attached garages were affected the most by parked vehicles, followed by homes with vehicles in carports. Concentrations in homes with cars in detached garages were similar to those in residences without cars. Low ventilation rates exacerbated C_in in homes with attached garages. In general, the contribution from gasoline-related sources to indoor benzene and MTBE concentrations appeared to have been dominated by car exhaust, or by a combination of tailpipe and gasoline vapor emissions. Residing in a home with an attached garage could lead to benzene exposures that are an order of magnitude higher than exposures from commuting in a car in heavy traffic, with a risk of 17 excess cancers in a population of a million. Strategies to lower exposure to gasoline-related contaminants in homes include improving construction practices to prevent the infiltration of pollutants into the living quarters or incorporating detached garages.     

Investigating the mechanism of phenol photooxidation by humic substances

To probe the mechanism of the photosensitized loss of phenols by humic substances (HS), the dependence of the initial rate of 2,4,6-trimethylphenol (TMP) loss (R(TMP)) on dioxygen concentration was examined both for a variety of untreated as well as borohydride-reduced HS and C(18) extracts from the Delaware Bay and Mid-Atlantic Bight. R(TMP) was inversely proportional to dioxygen concentration at [O(2)] > 50 μM, a dependence consistent with reaction with triplet excited states, but not with (1)O(2) or RO(2). Modeling the dependence of R(TMP) on [O(2)] provided rate constants for TMP reaction, O(2) quenching, and lifetimes compatible with a triplet intermediate. Borohydride reduction significantly reduced TMP loss, supporting the role of aromatic ketone triplets in this process. However, for most samples, the incomplete loss of sensitization following borohydride reduction, as well as the inverse dependence of R(TMP) on [O(2)] for these samples, suggests that there remains another class of oxidizing triplet sensitizer, perhaps quinones.     

GigaManP2P: an overlay network for distributed QoS management and resilient routing

Management of long‐distance, high‐speed optical backbones spanning multiple administrative domains requires new solutions for challenging tasks. In particular, it is not trivial to negotiate, monitor and continuously enforce the required quality of service (QoS) for applications that span multiple domains. This paper proposes GigaManP2P: a novel peer‐to‐peer (P2P) management architecture for high‐speed QoS‐aware backbones. GigaManP2P peers provide management services in a ubiquitous fashion through modules that interface with both the communication infrastructure and network users. In particular, we describe management services for on inter‐domain QoS monitoring and resilient routing. After detecting a QoS constraint violation trend, a proactive rerouting strategy is triggered based on redundant virtual circuits, allowing both full and partial rerouting. The P2P overlay implementation is the basis for allowing transparent communication across autonomous systems. Experimental results showing the overhead of the P2P infrastructure in comparison to raw Simple Network Management Protocol, and the performance of the rerouting strategy, are presented. Copyright © 2011 John Wiley & Sons, Ltd.