4-bit high speed R-2R Ladder Digital to Analog Converter (DAC) design is presented in this paper. The high speed DAC design uses a high speed InGaAs/GaAs HEMT device in its summer block. This paper justifies the use of HEMT devices for high speed converter applications. A detailed analysis of the DAC parameters and errors is presented. DAC performance up to 20GHz is presented and it shows very ...

Hyperpnoea of canine peripheral airways with dry air results in airway obstruction, mucosal damage, and inflammation. The purpose of this study was to evaluate the effect of repeated dry air challenge (DAC) on airway obstruction, reactivity and the development of airway inflammation in dogs. Canine peripheral airways received DAC (delivered under general anaesthesia through a bronchoscope) ever...

Recently, various multibit noise-shaping digital-toanalog converters (DAC’s) have been proposed that use digital signal processing techniques to cause the DAC noise arising from analog component mismatches to be spectrally shaped. Such DAC’s have the potential to significantly increase the present precision limits of data converters by eliminating the need for one-bit quantization in delta-sigm...

Deacylcortivazol (DAC), a potent glucocorticoid, contains a phenyl-pyrazole moiety fused to the 2--3 position of the traditional steroid nucleus. When incubated with glucocorticoid-resistant mutants derived from the glucocorticoid-sensitive human leukemic cell line CEM-C7, DAC caused significant growth inhibition. However, this effect required 1 microM DAC, a concentration 50 times higher than ...

DNA hypermethylation, an epigenetic change that silences gene expression without altering nucleotide sequences, plays a critical role in the formation and progression of colorectal cancers as well as in the acquisition of drug resistance. Decitabine (DAC), a DNA methyltransferase 1 inhibitor of nucleoside analogues, has been shown to restore gene expression silenced by hypermethylation. In the ...

Autophagy is a cellular bulk degradation pathway implicated in various diseases. Inhibition of autophagy has been regarded as a new therapeutic strategy for cancer treatment, especially in combination with chemotherapy. In our study, we identified two natural compounds, dauricine (DAC) and daurisoline (DAS), as two potent autophagy blockers through a high-content screening. DAC and DAS are alka...

Azacitidine (AZA) and decitabine (DAC) are cytidine azanucleoside analogs with clinical activity in myelodysplastic syndromes (MDS) and potential activity in solid tumors. To better understand the mechanism of action of these drugs, we examined the effects of AZA and DAC in a panel of non-small cell lung cancer (NSCLC) cell lines. Of 5 NSCLC lines tested in a cell viability assay, all were sens...

By Zhihe Zhou, Ph.D. Washington State University August 2006 Chair: George S. La Rue We investigated the design and implementation of non-linear D/A converters (DAC) for a direct digital frequency synthesizer (DDFS), which consists of a phase accumulator, a phase-to-sine look-up table and a DAC. Using a non-linear DAC can significantly reduce the look-up table size, hence, reducing the power di...

Ali K. Nahar University of Technology, Department of Electrical Engineering Abstract A first order of DWA (data weighted averaging) technique is proposed to improve 6-bit digital-to-analog convertor (DAC). In addition, this paper discusses the impact of mismatch between DAC unit elements. The simulation results show the effectiveness of the DWA technique in reduction of inband tones, also DWA t...