• ETRI Journal
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• 제34권4호
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• pp.518-526
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• 2012

This paper proposes LC voltage-controlled oscillator (VCO) phase-locked loop (PLL) and ring-VCO PLL topologies with low-phase noise. Differential control loops are used for the PLL locking through a symmetrical transformer-resonator or bilaterally controlled varactor pair. A differential compensation mechanism suppresses out-band spurious tones. The prototypes of the proposed PLL are implemented in a CMOS 65-nm or 45-nm process. The measured results of the LC-VCO PLL show operation frequencies of 3.5 GHz to 5.6 GHz, a phase noise of -118 dBc/Hz at a 1 MHz offset, and a spur rejection of 66 dBc, while dissipating 3.2 mA at a 1 V supply. The ring-VCO PLL shows a phase noise of -95 dBc/Hz at a 1 MHz offset, operation frequencies of 1.2 GHz to 2.04 GHz, and a spur rejection of 59 dBc, while dissipating 5.4 mA at a 1.1 V supply.

• Molecules and Cells
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• 제37권4호
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• pp.275-285
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• 2014

Macrophages, found in circulating blood as well as integrated into several tissues and organs throughout the body, represent an important first line of defense against disease and a necessary component of healthy tissue homeostasis. Additionally, macrophages that arise from the differentiation of monocytes recruited from the blood to inflamed tissues play a central role in regulating local inflammation. Studies of macrophage activation in the last decade or so have revealed that these cells adopt a staggering range of phenotypes that are finely tuned responses to a variety of different stimuli, and that the resulting subsets of activated macrophages play critical roles in both progression and resolution of disease. This review summarizes the current understanding of the contributions of differentially polarized macrophages to various infectious and inflammatory diseases and the ongoing effort to develop novel therapies that target this key aspect of macrophage biology.

• Animal cells and systems
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• 제2권4호
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• pp.489-493
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• 1998

Various heterodimers of the thyroid hormone receptor (TR) with other nuclear hormone receptors confer a wide range of transcriptional activities on thyroid hormone response elements (TREs) in the presence of the thyroid hormone ($T_3$). The present study analyzed the potential roles of retinoid X receptor (RXR) isoforms $\alpha$ and $\beta$ in $T_3$-mediated transcription on a well characterized TRE, a direct repeat of AGGTCA separated by four nucleo-tides (DR4), using electrophoretic mobility shift assays and transient transfection in CV-1 cells. We demonstrated that RXR$\alpha$ supressed liganded $TR_{\alpha}$-induced transcription while $RXR_{\beta}$ did not although both $TR_{\alpha}/RXR_{\alpha}$ and $TR_{\alpha}/RXR_{\beta}$ heterodimers were the predominant forms bound to the TRE-DR4 in the presence of $T_3$. We further demonstrated using Scatchard analysis that the two heterodimers had similar affinities for the TRE-DR4. All these observations suggest that the TRE-DR4 accomodates different types of TR/RXR heterodimers for a more finely tuned transcriptional response to $T_3$.

• Journal of Crop Science and Biotechnology
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• 제10권1호
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• pp.8-12
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• 2007

All accessions of Rehmannia glutinosa show the unique characteristic of intrinsic tolerance to paraquat. The higher level of endogenous superoxide dismutase(SOD) activity and its increase upon paraquat treatment indicated the involvement of SOD in the tolerance mechanism to paraquat in R. glutinosa. In this study, we examined the isoform-specific response of SOD to oxidative stresses and hormones. Six SOD isoforms were found in the leaf, and they were identified as two MnSODs(named MnSOD I and MnSOD II, in order of increasing mobility), one FeSOD and three Cu/ZnSODs(named Cu/ZnSOD I, Cu/ZnSOD II, and Cu/ZnSOD III, in order of increasing mobility). MnSOD I, MnSOD II, FeSOD, Cu/ZnSOD I, Cu/ZnSOD II, and Cu/ZnSOD III, contributed to 4, 11, 7, 15, 30, and 32% of the total SOD activity, respectively. Total SOD activity levels in the leaf were increased by 4, 24, and 21% by paraquat, salicylic acid(SA), and yeast extract(YE), respectively, but little by ethephon. Six SOD isoforms responded differentially to these stresses and hormones. The activities of all the isoforms were increased by YE and SA except that of MnSOD I which was decreased by SA. The activities of MnSOD I, FeSOD, and CuZnSOD I were increased by paraquat. These results suggest that amelioration of oxidative stresses by SOD is fine-tuned by the differential expression of isoforms in R. glutinosa.