Exercise-Induced Changes in Exhaled NO Differentiates Asthma With or Without Fixed Airway Obstruction From COPD With Dynamic Hyperinflation.

Asthmatic patients with fixed airway obstruction (FAO) and patients with chronic obstructive pulmonary disease (COPD) share similarities in terms of irreversible pulmonary function impairment. Exhaled nitric oxide (eNO) has been documented as a marker of airway inflammation in asthma, but not in COPD. To examine whether the basal eNO level and the change after exercise may differentiate asthmatics with FAO from COPD, 27 normal subjects, 60 stable asthmatics, and 62 stable COPD patients were studied. Asthmatics with FAO (n = 29) were defined as showing a postbronchodilator FEV(1)/forced vital capacity (FVC) ≤70% and FEV(1) less than 80% predicted after inhaled salbutamol (400 μg). COPD with dynamic hyperinflation (n = 31) was defined as a decrease in inspiratory capacity (ΔIC%) after a 6 minute walk test (6MWT). Basal levels of eNO were significantly higher in asthmatics and COPD patients compared to normal subjects. The changes in eNO after 6MWT were negatively correlated with the percent change in IC (r = −0.380, n = 29, P = 0.042) in asthmatics with FAO. Their levels of basal eNO correlated with the maximum mid-expiratory flow (MMEF % predicted) before and after 6MWT. In COPD patients with air-trapping, the percent change of eNO was positively correlated to ΔIC% (rs = 0.404, n = 31, P = 0.024). We conclude that asthma with FAO may represent residual inflammation in the airways, while dynamic hyperinflation in COPD may retain NO in the distal airspace. eNO changes after 6MWT may differentiate the subgroups of asthma or COPD patients and will help toward delivery of individualized therapy for airflow obstruction

Photocatalytic hydrogen generation with simultaneous organic degradation by composite CdS-ZnS nanoparticles under visible light

postprin

Partitioning of Phenylalanine Ammonia-lyase from Rhodotorula glutinis in Aqueous Two-phase Systems of PEG/salts

In this work, the partitioning of phenylalanine ammonia-lyase was investigated in different systems of PEG1000, PEG2000, PEG3350, PEG6000 and PEG8000 with (NH4)2SO4, Na2SO4, Na2CO3 and potassium phosphate. The results showed that the partition of phenylalanine ammonia-lyase in PEG/salt aqueous two-phase systems was mainly influenced by hydrophobicity, excluded volume effect and salting-out effect; compared with other PEG/salt systems, PEG1000/Na2SO4 was the most effective for phenylalanine ammonia-lyase partitioning. The result further supports that PEG/salt aqueous two-phase system provides a new and applicable route for the purification of phenylalanine ammonia-lyase, as shown in our published paper.1

Image annotation with parametric mixture model based multi-class multi-labeling

Author name used in this publication: Dagan FengRefereed conference paper2008-2009 > Academic research: refereed > Refereed conference paperVersion of RecordPublishe

The quasi-one-dimensional character of spin waves in K2Fe7Se8

published_or_final_versio

Constrained one-bit transform for retinex based motion estimation for sequences with brightness variations

Author name used in this publication: Dagan FengRefereed conference paper2007-2008 > Academic research: refereed > Refereed conference paperVersion of RecordPublishe

Modelling of nonlinear stochastic dynamical systems using neurofuzzy networks

Though nonlinear stochastic dynamical system can be approximated by feedforward neural networks, the dimension of the input space of the network may be too large, making it to be of little practical importance. The Nonlinear Autoregressive Moving Average model with eXogenous input (NARMAX) is shown to be able to represent nonlinear stochastic dynamical system under certain conditions. As the dimension of the input space is finite, it can be readily applied in practical application. It is well known that the training of recurrent networks using gradient method has a slow convergence rate. In this paper, a fast training algorithm based on the Newton-Raphson method for recurrent neurofuzzy network with NARMAX structure is presented. The convergence and the uniqueness of the proposed training algorithm are established. A simulation example involving a nonlinear dynamical system corrupted with the correlated noise and a sinusoidal disturbance is used to illustrate the performance of the proposed training algorithm.published_or_final_versio

Online fault detection and isolation of nonlinear systems

This paper describes an online fault detection scheme for a class of nonlinear dynamic systems with modelling uncertainty and inaccessible states. Only the inputs and outputs of the system can be measured. The faults are assumed to be functions of the state, instead of the output and the input of the system. A nonlinear online approximator using dynamic recurrent neural network is utilised to monitor the faults in the system. The construction and the learning algorithm of the online approximator are presented. The stability, robustness and sensitivity of the fault detection scheme under certain assumptions are analysed. An example demonstrates the efficiency of the proposed fault detection scheme.published_or_final_versio

Channel adaptive fair queueing for scheduling integrated voice and data services in multicode CDMA systems

CDMA (code division multiple access) systems are critical building blocks of future high performance wireless and mobile computing systems. While CDMA systems are very mature for voice services, their potentials in delivering high quality data services are yet to be investigated. One of the most crucial component in an advanced wideband CDMA system is the judicious allocation of bandwidth resources to both voice and high data rate services so as to maximize utilization while satisfying the respective quality of service requirements. Specifically, in a multicode CDMA system, the problem is to intelligently allocate codes to the users' requests. While previous work in the literature has addressed this problem from a capacity point of view, the fairness aspect, which is also important from the users' point of view, is largely ignored. In this paper, we propose a new code allocation approach that is channel adaptive and can guarantee fairness with respect to the users' channel conditions. Simulation results show that out approach is more effective than the proportional fair approach.published_or_final_versio

Dynamic conductance of mesoscopic waveguides

We report a theoretical investigation of dynamic conductance G(), for general ac frequency , of two-dimensional mesoscopic waveguides whose transport is characterized by antiresonances. We calculate G() by numerically evaluating nonequilibrium Green's functions. By tuning the ac frequency we observe photon-assisted resonant transport as well as a gradual smearing out of the antiresonances. The antiresonance causes the dynamic response to vary between capacitive-like behavior to that of the inductive-like behavior. © 2001 American Institute of Physics.published_or_final_versio