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Ubiquitin is a critical modifier regulating the degradation and function of its target proteins during posttranslational modification. Here we found that ubiquitin-specific peptidase 24 (USP24) is highly expressed in cell lines with enhanced malignancy and in late-stage lung cancer clinical samples. Studying single-nucleotide polymorphisms (SNPs) of USP24using genomic DNA of lung cancer patients revealed an increase in SNP 7656C/T. When using RNA specimens instead of the genomic DNA of lung cancer patients, we found significant increases in the ratios of variants 930C/T and 7656T/C, suggesting that variants at these two sites are not only caused by the SNP of DNA but also by the RNA editing. USP24-930Tand USP24-7656Cincrease USP24 expression levels by increasing RNA stability. Knocking down USP24increased Suv39h1 level through a decrease in mouse double-minute 2 homolog levels, thus enhancing lysine-9 methylation of histone H3, and resulting in the prevention of lung cancer malignancy. In conclusion, as USP24variant analysis revealed a higher ratio of variants in blood specimens of lung cancer patients than that in normal individuals, USP24-930Tand USP24-7656Cmight be useful as diagnostic markers for cancer detection.

Compliant manipulation tasks require the robot to follow a motion trajectory and to exert a force profile while making compliant contact with a dynamic environment. For this purpose, a generalized impedance in the task space is introduced such that the desired motion and the desired interaction force can be commanded and controlled simultaneously. Several control schemes which place different emphases on motion control or force control can be derived from the generalized impedance. The impedance-based control schemes are implemented and the performance evaluated on a common test-bed which involves the insertion of a printed circuit board into an edge connector socket. Experimental results demonstrate the superior motion and force tracking ability of the generalized impedance control method. Furthermore, safe task execution can be achieved in the presence of abnormal operating situation.

The success of robot assembly tasks depends heavily on its ability to handle the interactions which take place between the parts being assembled. In this paper, a robust motion-control method is presented for robot manipulators performing assembly tasks in the presence of dynamic constraints from the environment. Using variable structure model reaching control concept, the control objectives is first formulated as a performance model in the task space. A dynamic compensator is then introduced to form the switching function such that the sliding-mode matches the desired model. A simple variable structure control law is suggested to force the system to reach and stay on the sliding mode so that the specified model is achieved. The proposed method is applied to control the prismatic joint of a selective compliance assembly robot-arm type robot for the insertion of printed circuit board into an edge connector socket. Various amounts of interaction forces are generated during the operation. Experimental and simulation results demonstrated the performance of the variable structure model reaching control approach. In comparison, it is shown that the popular position controllers such as proportional plus derivative control and proportional plus derivative with model-based feedforward control are not suitable for achieving good trajectory tracking accuracy in assembly tasks which experience potential interaction force.

The purpose of this paper is to review the subject of oxygen and carbon in silicon crystals in terms of: 1) their origin and concentration; 2) their effect on the formation of crystalline defects and the impact of these on IC devices; and 3) the industrial trends regarding problems related to oxygen and carbon.

A differentially coherent (DC) correlation scheme is proposed for rapid DS-SS code acquisition in a fast Rayleigh fading channel. It is analytically shown that a serial-search DC acquisition system significantly outperforms the conventional parallel-search I-Q system in a highly dynamic environment.

A study was carried out to develop methods for reduction of defects in SIMOX (Separation of silicon by IMplantation of OXygen) material. Reduction of threading dislocations was demonstrated by utilizing multiple implant/anneal cycle and by misfit dislocations formed at the interface of Si1-xGex/Si heterostructure grown onto SIMOX substrate. The former method can reduce threading dislocations to less than 105cm-2in 0.1 µm silicon on insulator (SOI) and the latter method to 4×107cm-2in 3.1 µm SOI from approximately 109cm -2. To reduce oxide precipitates, two-step anneal was adopted: hydrogen ambient anneal at 850°C followed by standard inert ambient anneal at 1250°C. The oxygen bump seen in an oxygen depth profile of superficial silicon layer was almost eliminated. Linewidth of Raman scattering spectra was also improved from 4.45 cm-1by conventional anneal to 4.19 cm-1by this technique.