Abstract. In general computing systems, a job (process/task) may suspend itself whilst it is waiting for some activity to complete, e.g., an accelerator to return data. In real-time systems, such self-suspension can cause substantial performance/schedulability degradation. This observation, first made in 1988, has led to the investigation of the impact of self-suspension on timing predictability, and many relevant results have been published since. Unfortunately, as it has recently come to light, a number of the existing results are flawed. To provide a correct platform on which future research can be built, this paper reviews the state of the art in the design and analysis of scheduling algorithms and schedulability tests for self-suspending tasks in real-time systems. We provide (1) a systematic description of how self-suspending tasks can be handled in both soft and hard real-time systems; (2) an explanation of the existing misconceptions and their potential remedies; (3) an assessment of the influence of such flawed analyses on partitioned multiprocessor fixed-priority scheduling when tasks synchronize access to shared resources; and (4) a discussion of the computational complexity of analyses for different self-suspension task models.

A novel compact resonator for LPF is proposed in this paper. It is composed of a circular hairpin resonator and a pair of coupled parallel stepped impedance resonators (SIRs) inside. With the loaded SIRs, additional two transmission zeros can be introduced and adjusted easily to cancel the spurious responses for stopband extending, while do not change the filter size. Filters using one and two of the new cells were designed and measured. The two-cell LPF has an insertion loss less than 0.6 dB from DC to 1.6 GHz, including attenuation of double SMA transitions at both sides of the circuit which is about 0.3 dB and a wide −10 dB stopband from 2.5 to 13 GHz (corresponding to 146% normalized 10 dB stopband), but has a size of only 0.129λg × 0.073λg.

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The aim of this study was to investigate the role of P-glycoprotein (P-gp) in the intestinal absorption of triptolide. In this research, the bidirectional transport of triptolide across Caco-2 cells was studied in vitro. Moreover, the pharmacokinetic profiles of orally administered triptolide with and without pretreatment with verapamil were determined in rats. A markedly higher transport of triptolide across Caco-2 cells was observed in the basolateral-to-apical direction and was abrogated in the presence of the P-gp inhibitor, verapamil. The result indicated that P-gp might be involved in the absorption of triptolide. When the rats were pretreated with verapamil, the C max of triptolide increased from 423.01 ± 19.59 to 565.33 ± 20.27 ng/mL (33.6 %), and the AUC0-6 h increased by approximately 57 % when co-administered with verapamil. It was demonstrated that P-gp was involved in the transport of triptolide, which might exhibit a role in limiting its absorption and attenuating the toxicity of triptolide.