Protective Effects of Hydrogen against Low-Dose Long-Term Radiation-Induced Damage to the Behavioral Performances, Hematopoietic System, Genital System, and Splenic Lymphocytes in Mice

Molecular hydrogen (H2) has been previously reported playing an important role in ameliorating damage caused by acute radiation. In this study, we investigated the effects of H2 on the alterations induced by low-dose long-term radiation (LDLTR). All the mice in hydrogen-treated or radiation-only groups received 0.1 Gy, 0.5 Gy, 1.0 Gy, and 2.0 Gy whole-body gamma radiation, respectively. After the last time of radiation exposure, all the mice were employed for the determination of the body mass (BM) observation, forced swim test (FST), the open field test (OFT), the chromosome aberration (CA), the peripheral blood cells parameters analysis, the sperm abnormality (SA), the lymphocyte transformation test (LTT), and the histopathological studies. And significant differences between the treatment group and the radiation-only groups were observed, showing that H2 could diminish the detriment induced by LDLTR and suggesting the protective efficacy of H2 in multiple systems in mice against LDLTR

MAC-Layer QoS Management for Streaming Rate-Adaptive VBR Video over IEEE 802.11e HCCA WLANs

With the increasing popularity of using WLANs for Internet access, the HCCA mechanism in IEEE 802.11e WLANs has received much more attention due to its efficiency in handling time-bounded multimedia traffic. To achieve high network utilization and good end-to-end QoS in the scenario of VBR video over HCCA is a very challenging task because of the dynamics coming from both the network conditions and the video content. In this paper, we propose a cross-layer framework for efficiently delivering multiclass rate-adaptive VBR video over HCCA. The proposed framework consists of three major modules: the MAC-layer admission control, the MAC-layer resource allocation, and the application-layer video adaptation. Experimental results demonstrate the effectiveness of each individual module and the advantage of dynamic interactions among different modules

Channel Resource Allocation for VoIP Applications in Collaborative IEEE 802.11/802.16 Networks

Collaborations between the IEEE 802.11 and the IEEE 802.16 networks operating in a common spectrum offers dynamic allocate bandwidth resources to achieve improved performance for network applications. This paper studies the bandwidth resource allocation of collaborative IEEE 802.11 and IEEE 802.16 networks. Consider delivering data packets between mobile stations and Internet users through an access point (AP) of the IEEE 802.11 network and a base station (BS) of the IEEE 802.16 network operating on a common frequency band, we analyze their medium access control (MAC) protocols, frame structures, and design a cooperation mechanism for the IEEE 802.11 and the IEEE 802.16 networks to share the same medium with adaptive resource allocation. Based on the mechanism, an optimized resource allocation scheme is proposed for VoIP applications. An analytical model is developed for the study to show significant improvements in voice capacity for our optimized resource allocation scheme.</p

Design of ultra-low-power 60-GHz direct-conversion receivers in 65-nm CMOS

This paper has explored an ultra-low-power design of two 60-GHz direct-conversion receivers in a 65-nm CMOS process for single-channel and multi-channel applications under the IEEE 802.15.3c standard, respectively. One subthreshold biasing 0.4-V transconductance mixer is designed with a compact quadrature hybrid coupler (160 μm × 210 μm with measured 3-dB intrinsic loss) in receivers to achieve low power (8 mW for single channel and 12.4 mW for multi-channel) and high gain (55 dB for single channel and 62-dB for multi-channel). One three-stage low-noise amplifier employs high- Q passive matchings. A double-layer-stacked inductor is utilized for matching in the single-channel receiver and a high-impedance transmission line is utilized for matching in the multi-channel receiver, respectively. In addition, one new modified Cherry-Hooper amplifier is applied for the variable-gain amplifier design to achieve high gain-bandwidth product and high power efficiency. The single-channel receiver is implemented with 0.34- mm2 chip area. It is measured with a power consumption of 8 mW, a minimum single-sideband noise figure (NF) of 4.9 dB, a 3-dB bandwidth of 3.5 GHz, and a maximum conversion gain of 55 dB. The multi-channel receiver is implemented with 0.56- mm2 chip area. It is measured with a power consumption of 12.4 mW, a 3-dB bandwidth of 8 GHz (59.5 ~ 67.5 GHz), and a maximum conversion gain of 62 dB. The measurement results show that the two demonstrated 60-GHz direct-conversion receivers can achieve high gain and low NF with ultra-low power in 65-nm CMOS.Accepted versio

Admission Control Based on Rate-Variance Envelop for VBR Traffic over IEEE 802.11e HCCA WLANs ∗

published in the IEEE GLOBECOM 2006

80 GHz on-chip metamaterial resonator by differential transmission line loaded with split ring resonator

An on-chip metamaterial resonator is demonstrated in 65 nm CMOS at 80 GHz for millimetre-wave integrated circuit (MMIC) applications. The resonator is based on a differential metamaterial transmission-line (T-line) loaded with a split ring resonator (SRR), which can enhance the EM energy coupling and further improve the quality factor (Q). Measurement results indicate that the proposed differential SRR (DSRR) T-line shows a sharp stopband with maximum 35 dB rejection. Moreover, the metamaterial property of the DSRR T-line is validated from the measurement results. It is the first on-chip demonstration of a millimetre-wave metamaterial resonator in 65 nm CMOS, which can be integrated for a low-noise oscillator and high-Q filter design in a 100 GHz MMIC communication system.Accepted versio