Colorectal cancer is one of the most common malignancies. Aberrant expressed microRNAs (miRNAs) have been demonstrated to have strong associations with colorectal cancer by repressing their targets. Therefore, miRNAs are thought to have significant promise in the diagnosis and prognosis of colorectal cancer. Previous studies indicated that miR-155 and collagen triple helix repeat containing 1 (CTHRC1) were both involved in pathogenesis of colorectal cancer, but the underlying mechanisms of miR-155 and CTHRC1 are still unknown. The present study aimed to investigate the biological functions of miR-155 and CTHRC1 in colorectal cancer. Reverse transcription-quantitative polymerase chain reaction was used to examine miR-155 and CTHRC1 expression levels. A dual-luciferase reporter assay was applied to verify the target interaction between miR-155 and CTHRC1. Proliferation, cell cycle, apoptosis, cell migration and invasion were measured using the MTT assay, flow cytometry and Transwell assays, respectively. Results showed that miR-155 expression was decreased, but CTHRC1 expression was increased in colorectal cancer tissue and cell lines. Furthermore, it was demonstrated that miR-155 negatively regulated CTHRC1. Additionally, miR-155 overexpression suppressed cell proliferation, induced cell cycle arrest and promoted cell apoptosis, while an inhibitor of miR-155 facilitated cell proliferation and cell cycle and repressed apoptosis. Transwell experiments indicated that miR-155 inhibited the cell migratory and invasive abilities of HT-29 cells, but miR-155 inhibitor enhanced these abilities of HT-29 cells. These results suggested that miR-155 prevented colorectal cancer progression and metastasis via silencing CTHRC1 in vitro, which provides evidence for miR-155 and CTHRC1 as a novel anti-onco molecular target for the treatment of colorectal cancer in the future.
Surface acoustic wave (SAW) devices using embedded interdigital transducers (IDTs) on an AlN/diamond/Si layered substrate are fabricated, and their performances are investigated. The Sezawa mode is the dominant resonance with the highest resonant frequency up to 17.7 GHz, a signal amplitude of 20 dB, and an electromechanical coupling coefficient of 0.92%. Comparing these SAW devices with those having the conventional IDTs on the same layered structure, the output SAW power and resonant frequency of devices are improved by 10.7% and 1.1%, respectively, for the embedded IDT devices. This is because the different field distribution leads to the different Bragg reflection and phase velocity for the two types of IDTs. The radiation frequency characteristics indicate that the advantages of the embedded IDTs would be useful for high frequency, high power applications such as monolithic integrated millimeter-wave integrated circuit and high speed communications.
In nanometer bulk CMOS processes, multi-node charge collection induced by a heavy-ion strike is prevalent. Pulse quenching caused by charge sharing between the struck node (termed as active device) and the following gate (termed as passive device) has been widely studied in digital circuits. This paper firstly demonstrates that the pulse quenching effect also exists between the adjacent stages of analog circuits and can be used to mitigate analog single-event transient (ASET) perturbation. Contrary to digital circuits, whose propagated SET is minimized with the charge collected by passive device maximized, simulation results indicate that there is an optimal spacing between the active and passive devices in analog circuits. When the spacing is too close, the SET induced by the hit node is efficiently mitigated by pulse quenching effect, but the disturbance caused by the charge sharing collection in passive device becomes dominant. Simulation results show that pulse quenching effect has a dual role in ASET mitigation. This paper provides innovative guidance to the radiation-hardening design for analog circuits.
In analog circuit design, the bulks of MOSFETs can be tied to their respective sources to remove body effect. This paper models and analyzes the sensitivity of single-event transients (SETs) in common source (CS) amplifier with bulk tied to source (BTS) in 40 nm twin-well bulk CMOS technology. The simulation results present that the proposed BTS radiation-hardened-by-design (RHBD) technique can reduce charge collection and suppress the SET induced perturbation effectively in various input conditions of the circuit. The detailed analysis shows that the mitigation of SET is primarily due to the forward-bias of bulk potential. This technique is universally applicable in radiation-hardening design for analog circuits with negligible penalty.
Dynamic threshold-voltage MOSFETs (DTMOSs) with bulk and gate tied together are commonly used in ultra-low voltage applications. Since the threshold voltage of the device is a function of its gate voltage, and the current-driving capability is boosted as the gate-source voltage increases, it has the potential to be applied in the community of radiation-hardened IC circuits. This paper firstly demonstrates that DTMOS is particularly suitable for analog single-event transient (ASET) mitigation in cascode current mirrors with negligible penalty. A basic current mirror and a cascode current mirror are modelled to analyze the devices in DTMOS configuration, and compare radiation performance with standard MOSFETs. Simulation results demonstrate that the DTMOS scheme reduces charge collection, and suppresses single-event effect-induced perturbation effectively in the cascode current mirror, while playing a detrimental role in basic current mirrors due to the well-known bipolar effect. This technique provides a novel method for mitigating ASET disturbances for the designers of spaceborne ICs.
Perovskite Ba 0.5 Sr 0.5 TiO 3 (BST) thin films with a thickness of 300 nm are deposited on high resistivity silicon through pulsed laser deposition. The permittivity of BST is changed by applying an external electrostatic field. Coplanar waveguides (CPWs) are designed to extract the fielddependent permittivity of the film in the frequency range from 1 GHz to 110 GHz. A Subregional Match 3-Dimensional finite element method (SM 3D FEM) is proposed to implement the permittivity extraction. We analysis the electric field distribution in BST film, and thus divide the BST film in a reasonable way in order to achieve the permittivity of each small region in BST film by S-parameters-phase matching. The relative difference between measured and simulated S-parameters-phase is defined to describe the precision of the result. Experimental results show that the relative difference is less than 1.3%. We also found that the permittivity tunability is almost unchanged in a wide frequency domain, the variation of the tunability less than 0.16. The relative dielectric permittivity ξ BST at 0 V equals 1148.9 at 1 GHz and reduces to 311.7 at 110 GHz, and ξ BST at 100 GHz equals 315.8 at 0 V and declines to 193.4 at 30 V. The tunability of BST film is about 38.7% at 100 GHz.
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