脂肪和肥胖相关蛋白(fat mass and obesity-associated protein, FTO)是N6-甲基腺苷(N6 -methyladenosine, m6A)调控系统中重要的去甲基化酶。既往研究发现,FTO在脑内的异常表达可影响神经元内一些基因的mRNA中m6A修饰水平的含量,在阿...脂肪和肥胖相关蛋白(fat mass and obesity-associated protein, FTO)是N6-甲基腺苷(N6 -methyladenosine, m6A)调控系统中重要的去甲基化酶。既往研究发现,FTO在脑内的异常表达可影响神经元内一些基因的mRNA中m6A修饰水平的含量,在阿尔茨海默病、帕金森病、创伤性脑损伤、脑缺血性疾病等多种神经系统疾病的发生发展中具有重要调控作用。本文主要针对FTO基因表达调控神经元损伤或凋亡的机制及其在多种神经系统疾病中的研究进展进行综述。展开更多
This paper presents a fully integrated RF front-end with an automatic gain control（AGC） scheme and a digitally controlled radio frequency varied gain amplifier（RFVGA） for a U/V band China Mobile Multimedia Broadca...This paper presents a fully integrated RF front-end with an automatic gain control（AGC） scheme and a digitally controlled radio frequency varied gain amplifier（RFVGA） for a U/V band China Mobile Multimedia Broadcasting（CMMB） direct conversion receiver.The RFVGA provides a gain range of 50 dB with a 1.6 dB step. The adopted AGC strategy could improve immunity to adjacent channel signal,which is of importance for CMMB application.The front-end,composed of a low noise amplifier（LNA）,an RFVGA,a mixer and AGC,achieves an input referred 3rd order intercept point（IIP3） of 4.9 dBm with the LNA in low gain mode and the RFVGA in medium gain mode,and a less than 4 dB double side band noise figure with both the LNA and the RFVGA in high gain mode.The proposed RF front-end is fabricated in a 0.35μm SiGe BiCMOS technology and consumes 25.6 mA from a 3.0 V power supply.展开更多
This paper presents the circuit design and measured performance of a multi-band tuner for mobile TV applications. The tuner RFIC is composed of a wideband front-end, an analog baseband, a full integrated fractional- N...This paper presents the circuit design and measured performance of a multi-band tuner for mobile TV applications. The tuner RFIC is composed of a wideband front-end, an analog baseband, a full integrated fractional- N synthesizer and an Iac digital interface. To meet the stringent adjacent channel rejection （ACR） requirements of mobile TV standards while keeping low power consumption and low cost, direct conversion architecture with a local AGC scheme is adopted in this design. Eighth-order elliptic active-RC filters with large stop band attenuation and a sharp transition band are chosen as the channel select filter to further improve the ACR preference. The chip is fabricated in a 0.35-#m SiGe BiCMOS technology and occupies a silicon area of 5.5 mm2. It draws 50 mA current from a 3.0 V power supply. In CMMB application, it achieves a sensitivity of-97 dBm with 1/2 coding QPSK signal input and over 40 dB ACR.展开更多
A 2.4 GHz, direct-conversion RF transmitter front-end with an up converter and PA driver is fabricated in a 0.13/zm CMOS process for the reliable transmission of 54 Mb/s OFDM signals. The front-end output power is -3 ...A 2.4 GHz, direct-conversion RF transmitter front-end with an up converter and PA driver is fabricated in a 0.13/zm CMOS process for the reliable transmission of 54 Mb/s OFDM signals. The front-end output power is -3 dBm while the corresponding EVM is -27 dB which is necessary for the 802.11g standard of EVM at-25 dB. With the adopted gain control strategy the output power changes from -14.3 to -3.7 dBm with every step 0.8 dB （20%） which covers the gain variation due to working temperature and process. A power detector indicates the output power and delivers a voltage to the baseband to control the output power.展开更多
文摘脂肪和肥胖相关蛋白(fat mass and obesity-associated protein, FTO)是N6-甲基腺苷(N6 -methyladenosine, m6A)调控系统中重要的去甲基化酶。既往研究发现,FTO在脑内的异常表达可影响神经元内一些基因的mRNA中m6A修饰水平的含量,在阿尔茨海默病、帕金森病、创伤性脑损伤、脑缺血性疾病等多种神经系统疾病的发生发展中具有重要调控作用。本文主要针对FTO基因表达调控神经元损伤或凋亡的机制及其在多种神经系统疾病中的研究进展进行综述。
文摘This paper presents a fully integrated RF front-end with an automatic gain control（AGC） scheme and a digitally controlled radio frequency varied gain amplifier（RFVGA） for a U/V band China Mobile Multimedia Broadcasting（CMMB） direct conversion receiver.The RFVGA provides a gain range of 50 dB with a 1.6 dB step. The adopted AGC strategy could improve immunity to adjacent channel signal,which is of importance for CMMB application.The front-end,composed of a low noise amplifier（LNA）,an RFVGA,a mixer and AGC,achieves an input referred 3rd order intercept point（IIP3） of 4.9 dBm with the LNA in low gain mode and the RFVGA in medium gain mode,and a less than 4 dB double side band noise figure with both the LNA and the RFVGA in high gain mode.The proposed RF front-end is fabricated in a 0.35μm SiGe BiCMOS technology and consumes 25.6 mA from a 3.0 V power supply.
文摘This paper presents the circuit design and measured performance of a multi-band tuner for mobile TV applications. The tuner RFIC is composed of a wideband front-end, an analog baseband, a full integrated fractional- N synthesizer and an Iac digital interface. To meet the stringent adjacent channel rejection （ACR） requirements of mobile TV standards while keeping low power consumption and low cost, direct conversion architecture with a local AGC scheme is adopted in this design. Eighth-order elliptic active-RC filters with large stop band attenuation and a sharp transition band are chosen as the channel select filter to further improve the ACR preference. The chip is fabricated in a 0.35-#m SiGe BiCMOS technology and occupies a silicon area of 5.5 mm2. It draws 50 mA current from a 3.0 V power supply. In CMMB application, it achieves a sensitivity of-97 dBm with 1/2 coding QPSK signal input and over 40 dB ACR.
文摘A 2.4 GHz, direct-conversion RF transmitter front-end with an up converter and PA driver is fabricated in a 0.13/zm CMOS process for the reliable transmission of 54 Mb/s OFDM signals. The front-end output power is -3 dBm while the corresponding EVM is -27 dB which is necessary for the 802.11g standard of EVM at-25 dB. With the adopted gain control strategy the output power changes from -14.3 to -3.7 dBm with every step 0.8 dB （20%） which covers the gain variation due to working temperature and process. A power detector indicates the output power and delivers a voltage to the baseband to control the output power.
