A low power 433 MHz CMOS （complementary metal- oxide-semiconductor transistor） low noise amplifier（LNA）, used for an ISM （ industrial-scientific-medical ） receiver, is implemented in a 0. 18 μm SMIC mixed-signa...A low power 433 MHz CMOS （complementary metal- oxide-semiconductor transistor） low noise amplifier（LNA）, used for an ISM （ industrial-scientific-medical ） receiver, is implemented in a 0. 18 μm SMIC mixed-signal and RF （ radio frequency） CMOS process. The optimal noise performance of the CMOS LNA is achieved by adjusting the source degeneration inductance and by inserting an appropriate capacitance in parallel with the input transistor of the LNA. The measured results show that at 431 MHz the LNA has a noise figure of 2.4 dB. The S21 is equal to 16 dB, S11 = -11 dB, S22 = -9 dB, and the inverse isolation is 35 dB. The measured input 1-dB compression point （PtdB） and input third-order intermodulation product （IIP3）are - 13 dBm and -3 dBm, respectively. The chip area is 0. 55 mm × 1.2 mm and the DC power consumption is only 4 mW under a 1.8 V voltage supply.展开更多
Recently,some of the genetic mechanisms of heart specification have been elucidated in Drosophila .However,genes involved in early cardiogenesis of human remain to be identified.Since the pathways that regulate ear...Recently,some of the genetic mechanisms of heart specification have been elucidated in Drosophila .However,genes involved in early cardiogenesis of human remain to be identified.Since the pathways that regulate early cardiac fate determination are conserved between Drosophila and vertebrates,flies can be used as a model test system to explore the genetic basis of cardiogenesis in human.In this project,about 3000 reccieve lethal gene lines were produced by P or EMS mutagenesis.With staining of antibodies against heart precussor cells of Drosophila ,about 200 lines were observed to show heart phenotype.In pilot studies of their function with RNAi technique,the RNAi phenotypes of several genes tested were observed,which were very similar to that of their mutants,showing heart tube defects or no heart precursors formation.Taking advantage of the advanced genetic information available in the Drosophila and human systems,we have identified about 50 human transcripts homologous to the Drosophila heart related gene candidates.Northern blot analysis for some of the human candidates showed that several genes were expressed in both adult and early embryonic tissues,which may help in the evaluation of candidate genes for human cardiogenesis.Our further experiments with transgenic flies generated with wild type and mutant forms of these candidate genes to examine for defects in cardiogenesis or cardiac function are under way.The candidate genes producing cardiac specific defects suggestive of similarities to the heart disease syndromes can then be pursued further as likely disease gene candidates.Such an approach is likely to provide a dramatic reduction of possible candidate genes,or to screen and identify mutations that may generate the disease in human.展开更多
基金The National Natural Science Foundation of China (No.60772008)the Key Science and Technology Program of Zhejiang Province(No.G2006C13024)
文摘A low power 433 MHz CMOS （complementary metal- oxide-semiconductor transistor） low noise amplifier（LNA）, used for an ISM （ industrial-scientific-medical ） receiver, is implemented in a 0. 18 μm SMIC mixed-signal and RF （ radio frequency） CMOS process. The optimal noise performance of the CMOS LNA is achieved by adjusting the source degeneration inductance and by inserting an appropriate capacitance in parallel with the input transistor of the LNA. The measured results show that at 431 MHz the LNA has a noise figure of 2.4 dB. The S21 is equal to 16 dB, S11 = -11 dB, S22 = -9 dB, and the inverse isolation is 35 dB. The measured input 1-dB compression point （PtdB） and input third-order intermodulation product （IIP3）are - 13 dBm and -3 dBm, respectively. The chip area is 0. 55 mm × 1.2 mm and the DC power consumption is only 4 mW under a 1.8 V voltage supply.
文摘Recently,some of the genetic mechanisms of heart specification have been elucidated in Drosophila .However,genes involved in early cardiogenesis of human remain to be identified.Since the pathways that regulate early cardiac fate determination are conserved between Drosophila and vertebrates,flies can be used as a model test system to explore the genetic basis of cardiogenesis in human.In this project,about 3000 reccieve lethal gene lines were produced by P or EMS mutagenesis.With staining of antibodies against heart precussor cells of Drosophila ,about 200 lines were observed to show heart phenotype.In pilot studies of their function with RNAi technique,the RNAi phenotypes of several genes tested were observed,which were very similar to that of their mutants,showing heart tube defects or no heart precursors formation.Taking advantage of the advanced genetic information available in the Drosophila and human systems,we have identified about 50 human transcripts homologous to the Drosophila heart related gene candidates.Northern blot analysis for some of the human candidates showed that several genes were expressed in both adult and early embryonic tissues,which may help in the evaluation of candidate genes for human cardiogenesis.Our further experiments with transgenic flies generated with wild type and mutant forms of these candidate genes to examine for defects in cardiogenesis or cardiac function are under way.The candidate genes producing cardiac specific defects suggestive of similarities to the heart disease syndromes can then be pursued further as likely disease gene candidates.Such an approach is likely to provide a dramatic reduction of possible candidate genes,or to screen and identify mutations that may generate the disease in human.
