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Methylated cell-free DNA (cfDNA) has been regarded as a novel indicator for early diagnosis and prognosis of ovarian cancer. However, analysis the methylation status of tumor suppressor genes in cfDNA remains challenging due to its extremely low concentration and lengthy, labor-intensive processes. In this study, an integrated microfluidic chip was reported to use beads coated with methyl CpG binding proteins and functional microfluidic devices which could implement (1) capture of methylated cfDNA in plasma and (2) semi-quantitative methylation-status analysis of tumor suppressor genes. The limit of detection could be as low as 2 pg/µL, which is two orders of magnitude lower than the previous work. Moreover, a dynamic range from 2 to 200 pg/µL of methylated cfDNA could be achieved. The whole process could be automated in 2 hr while only required 20 µL of plasma, indicating that this integrated microfluidic system may be utilized for early diagnosis and prognosis of ovarian cancer by using liquid biopsy.

In this paper, an innovative passive equalizer that is also able to filter common-mode noise is proposed, which is realized based on a via-conducted coplanar waveguide structure with resistive load (VCPW-R) formed on the ground plane. The proposed structure is low cost, compact and easily designed. Based on the analyses of the odd mode and even mode, a co-design flow is established, with which a set of design parameters are determined for 10 Gbps differential transmission and utilized in test-board fabrication. The effectiveness of the proposed structure is validated by the frequency-domain measurement result and time-domain simulation result of the test board.

A physics-based equivalent circuit model of on-chip decoupling capacitor for chip modelling is proposed for use in accurate power integrity (PI) analysis. The proposed model can be easily applied to on-chip decoupling capacitor design based on the construction flow. The accuracy of the model has been verified with circuit simulation. By using this model and an incomplete one, a case study of chip-package co-simulation in H-spice environment is investigated, which successfully demonstrate the purpose of the proposed model.

Rate adaptation is a common technique to exploit channel diversity in wireless networks. Despite the many rate adaptation algorithms proposed for 802.11 networks, the ARF (auto rate fallback) remains the most widely adopted scheme in commercial 802.11 products due to its simplicity. However, ARF suffers from some disadvantages. Our research effort revealed the rate avalanche effect that could significantly degrade the network performance of heavily loaded 802.11 networks. In this work, we propose RADAR (Rate-Alert DynAmic Rts/cts exchange) to judiciously exploit dynamic RTS/CTS exchange in multi-rate 802.11 networks. RADAR could effectively suppress the rate avalanche effect while at the same time minimizes the transmission overhead of RTS/CTS exchanges. Being fully compatible with current 802.11 standards, RADAR can be readily implemented in the NIC driver. Through extensive simulations using realistic channel propagation and reception models, we demonstrate that RADAR is a practical and efficient performance enhancement approach for multi-rate 802.11 networks.

The request-to-send/clear-to-send (RTS/CTS) exchange was defined as an optional mechanism in DCF (distributed coordination function) access method in IEEE 802.11 standard to deal with the hidden node problem. However, in most infrastructure-based WLANs, it is turned off with the belief that the benefit it brings might not even be able to pay off the transmission overhead it introduces. While this is often true for networks using fixed transmission rate, our investigation leads to the opposite conclusion when multiple transmission rates are exploited in WLANs. In particular, through extensive simulations using realistic channel propagation and reception models, we found out that in a heavily loaded multi-rate WLAN, a situation that we call rate avalanche often happens if RTS/CTS is turned off. The rate avalanche effect could significantly degrade the network performance even if no hidden node presents. Our investigation also reveals that, in the absence of effective and practical loss-differentiation mechanisms, simply turning on the RTS/CTS could dramatically enhance the network performance in most cases. Various scenarios/conditions are extensively examined to study their impact on the network performance for RTS/CTS on and off respectively. Our study provides some important insights about using the RTS/CTS exchange in mutlirate 802.11 WLANs.