Browsing by Subject "Oxides"

Now showing 1 - 2 of 2

Open Access
CMOS-based carbon nanotube pass-transistor logic integrated circuits.
(Nature communications, 2012-02) Ding, Li; Zhang, Zhiyong; Liang, Shibo; Pei, Tian; Wang, Sheng; Li, Yan; Zhou, Weiwei; Liu, Jie; Peng, Lian-Mao
Field-effect transistors based on carbon nanotubes have been shown to be faster and less energy consuming than their silicon counterparts. However, ensuring these advantages are maintained for integrated circuits is a challenge. Here we demonstrate that a significant reduction in the use of field-effect transistors can be achieved by constructing carbon nanotube-based integrated circuits based on a pass-transistor logic configuration, rather than a complementary metal-oxide semiconductor configuration. Logic gates are constructed on individual carbon nanotubes via a doping-free approach and with a single power supply at voltages as low as 0.4 V. The pass-transistor logic configurarion provides a significant simplification of the carbon nanotube-based circuit design, a higher potential circuit speed and a significant reduction in power consumption. In particular, a full adder, which requires a total of 28 field-effect transistors to construct in the usual complementary metal-oxide semiconductor circuit, uses only three pairs of n- and p-field-effect transistors in the pass-transistor logic configuration.
Open Access
Iron oxide/manganese oxide co-loaded hybrid nanogels as pH-responsive magnetic resonance contrast agents.
(Biomaterials, 2015-01) Wang, Xia; Niu, Dechao; Wu, Qing; Bao, Song; Su, Teng; Liu, Xiaohang; Zhang, Shengjian; Wang, Qigang
This work described a proof of concept study of hybrid nanogel-based magnetic resonance contrast agents, SPIO@GCS/acryl/biotin@Mn-gel, abb. as SGM, for highly efficient, pH-responsive T1 and T2 dual-mode magnetic resonance imaging (MRI). SGM have been synthesized by assembling superparamagnetic iron oxide particles into polysaccharide nanoclusters, followed by in-situ reduction of the manganese species on the clusters and a final mild polymerization. The dual-mode SGM showed an interesting pH-responsiveness in in vitro MRI, with both T1 and T2 relaxivities turned "ON" in the acidic environment, along with an increase in the r1 and r2 relaxivity values by 1.7-fold (from 8.9 to 15.3 mM(-1) S(-1)) and 4.9-fold (from 45.7 to 226 mM(-1) S(-1)), due to desirable silencing and de-silencing effects. This interesting acidic-responsiveness was further verified in vivo with both significantly brightened signal of tumor tissue in T1-weighted MR images and a darkened signal in T2-weighted MR images 50 min post-injection of SGM. This smart hybrid nanogel may serve as a promising candidate for further studies of dual-mode (T1 and T2) contrast agents in MRI, due to its high stability, interesting pH-response mechanism and indicative imaging of tumors.