A QoS index for IP services to effectively support usage-based charging

The goal of this letter is to present a model to compute a quality-of-service (QoS) index to characterize IP services. Then, we show how such a score may be used in a clear and flexible way for defining advanced usage-based tariff criteria to charge QoS guaranteed network services to address the dynamics of the expected future telecommunications scenario.     

Traction-based Completed Adjoint Double Layer Boundary Element Method in elasticity

This paper is concerned with a traction-based Completed Adjoint Double Layer Boundary Element Method to solve for the surface traction of a system of rigid particles embedded in an elastic matrix. The main feature of the method is a single layer representation of the displacement field, which leads to a system of second-kind integral equations for the traction field, the extreme eigenvalue of which could be deflated, allowing iterative solution strategies to be effectively applied. The method is therefore most suitable for large-scale simulations of particulate solids. The method is benchmarked against some known analytic solutions, including the difficult stress singularity problems at sharp edges. The effectiveness of the method in dealing with a large number of inclusions is also demonstrated with an elongational deformation problem involving up to 25 inclusions.Research supported by the Australian Research Council (to NP-T and X-JF) and the National Natural Science Foundation of China (X-JF).     

Imaging of follicular dendritic cell tumours of the liver

Follicular dendritic cell tumour of the liver is a recently recognized entity. To date, only two cases have been described, both in the pathology literature. Histologically, it resembles an inflammatory pseudotumour and immunohistochemical and ultrastructural studies are required for its diagnosis. The ultrasound, computed tomography and angiographic features of two cases of follicular dendritic cell tumour of the liver are described in detail. One of the patients had multiple recurrences of this tumour. The imaging features are very similar to those of hepatocellular carcinoma. As follicular dendritic cell tumour is considered to be of low-grade malignant potential, in contrast to the dismal prognosis for hepatocellular carcinoma, it is important to be able to accurately distinguish between the two types of tumour prior to initiating definitive therapy.     

The novel inotropic agent CGP 48506 alters force primarily by Ca(2+)-independent mechanisms in porcine skinned trabeculae

OBJECTIVES: The aim was to determine whether, and by what mechanism(s), a novel inotropic agent 5-methyl-6-phenyl-1,3,5,6-tetrahydro-3, 6-methano-1,5-benzodiazocine-2,4-dione (BA 41899) and its enantiomers directly alter the Ca2+ sensitivity of cardiac myofilaments. METHODS: Porcine ventricular trabeculae were permeabilised with Triton X-100. The relationship between force and pCa (-log[Ca2+]) was determined in the presence and absence of ATP. Troponin I was extracted, using vanadate, to produce unregulated maximally activated myofilaments. Force and actomyosin ATPase activity were measured simultaneously to determine tension cost (ATPase activity/tension). The effects of the (+) enantiomer (CGP 48506) on the twitch of intact muscle were demonstrated using rat papillary muscle. RESULTS: 100 microM BA 41899 had a pronounced Ca2+ sensitising effect on force production by porcine skinned cardiac fibres, increasing the pCa required for 50% maximal activation by 0.64 units, while suppressing maximum force by 18.3%. Resting tension was unaffected. These actions were primarily caused by CGP 48506 and were concentration dependent. At concentrations less than 100 microM, CGP 48506 also increased twitch amplitude in intact papillary muscles with no effect on resting tension, whereas 100 microM CGP 48506 increased resting force due to a slowing of relaxation. 100 microM CGP 48506 potentiated Ca(2+)-independent rigor tension in skinned trabeculae, indicating a Ca2+ sensitising mechanism unrelated to Ca2+ binding to troponin C. Tension cost was unaffected by 100 microM CGP 48506 over the entire range of activating Ca2+ concentrations. Suppression of maximum force by CGP 48506 was independent of both Ca2+ concentration and the regulatory troponin complex. CONCLUSIONS: Both the increase in Ca2+ sensitivity during submaximal activation and the depression of maximum force which are induced by CGP 48506 in skinned trabeculae occur at least partly through Ca(2+)-independent mechanisms.     

Morphological variations of the human gastric mucosa after omeprazole treatment: a scanning electron microscopic study

The effects of antiepileptic drugs on cognitive function in 48 healthy volunteers were assessed using event-related potentials (ERP) and the Attention Index included in the Wechsler Memory Scale, revised edition (WMS-R). The study was conducted over 1 week, using a double-blind design. Four drugs, carbamazepine (CBZ), phenytoin (PHT), valproate (VPA) and zonisamide (ZNS) were tested. Using an auditory oddball task, ERP measurements were made under two conditions with different tone intensities: Condition 1 used 70 db SPL; and Condition 2 used 30 db SPL. Results showed that CBZ prolonged target N1 and P3 latencies in Condition 1, and reduced frequent N1 amplitude in Condition 2, which suggests that CBZ may cause a change in sensory memory and prolong stimulus evaluation time. It is suggested that under a low stimulus intensity level, the sensory function itself was affected. Phenytoin was found to prolong target N1 latency in Condition 2, which also indicates a change in the sensory memory function. However, VPA did not significantly affect ERP components, except for the shortened frequent N1 latency, which could not be explained due to the limited information. It was found that ZNS augmented P3 amplitude in Condition 2, and reduced scores on the Attention Index. It is suggested that the augmentation of P3 amplitude was caused by the reduction of processing negativity as a result of the detrimental effect of ZNS on subjects' attention. However, the apparent difference between the ERP and behavioral indices suggests that caution should be exercised in assessing the results obtained only from ERP measurements.     

A new minimum zone method for evaluating flatness errors

A new minimum zone method for flatnes error analyis is proposed in this article. Based on the criteria for the minimum zone solution and strict rules for data exchange, a simple and rapid algorithm, called the control plane rotation scheme, is developed for the flatness analysis of a flat surface. Experimental work was performed, and some examples are given in terms of the minimum zone and least-squares solutions.     

粘土作为高放废物处置回填材料的可行性研究

本文以西北粘土为对象,对其压实行为、热传导、膨胀特性,以及吸附和渗透性能进行了初步研究,借以探讨西北粘土在高放废物处置中用作回填材料的可行性。试验表明,以西北粘土为基材,经过适当的热改性和吸附改性,在初始含水量约为9%,于70MPa 下成型,用作高放废物处置中的回填材料是可行的。     

硫氰酸钠湿纺腈纶设备的孔蚀与防护

本文重点讨论了硫氰酸钠湿纺腈纶设备因钝化膜缺陷和Cl-侵入而产生孔蚀的机理及环境因素对孔蚀的影响,并针对产生孔蚀的主要原因提出了防护措施。