Objective To develop a universal quantitative immunoenzyme assay (EIA) for detecting amplified products of nucleic acid and its application in hepatit is C virus (HCV). Methods The appropriate cycle number of am...Objective To develop a universal quantitative immunoenzyme assay (EIA) for detecting amplified products of nucleic acid and its application in hepatit is C virus (HCV). Methods The appropriate cycle number of amplification was selected to s top polymerase chain reaction (PCR) before the “plateau stage”. At the same ti me, primers HCV(3) of the second PCR were modified with biotin so that the ampli fied products were labeled. The products were diluted and subsequently added t o the streptavidin coated wells, and the biotinylated products were captured, f ollowed by denaturation of NaOH, and non biotinylated strands were removed. Hy bridization was performed by adding the specific probe labeled with fluorescein. Finally anti fluorescein horse radish peroxidase (HRP) conjugates were added, after washing, 3,3',5,5', tetramethylbenzidine (TMB) was added to the well s and then measured on a microplate reader. Results EIA detection of amplified products of HCV showed that this ass ay was rapid, sensitive, specific and accurate. Correlation between the initial number of viral template and the EIA of amplified products was good. We also pro spectively investigated the response to interferon in five patients with HCV coi nfection. Results showed that this assay could be used as a guidance to the clin ical therapy in directing the use of antiviral drugs. Conclusions This assay could be widely used as a universal technique fo r the quantitative detection of amplified products of all nucleic acid (such as virus, bacterium) and other human genes (such as HLA B 27 ), it has vast vistas.展开更多
A low-power three-stage amplifier for driving large capacitive load is proposed. The feedback path formed by the active-feedback Miller capacitor leads to a high frequency complex-pole but a high Q-value, which signif...A low-power three-stage amplifier for driving large capacitive load is proposed. The feedback path formed by the active-feedback Miller capacitor leads to a high frequency complex-pole but a high Q-value, which significantly deteriorates the stability of the amplifier. The serial RC stage introduced as the second stage output load can optimize the resistor Rz and the capacitor Cz under fixed power and small compensation capacitor Ca, which brings about a suitable Q-value of the complex-pole and the gain-bandwidth product extension of the amplifier. The amplifiers were designed and implemented in a standard 65 nm CMOS process with capacitive loads of 500 p F and 2 n F, respectively. The post-layout simulation results show that the amplifier driving the 500 p F capacitive load can achieve a gain of 113 d B, a phase margin of 50.6° and a gain-bandwidth product of 5.22 MHz while consuming 24 μW from a 1.2 V supply. For the 2 n F capacitive load, the amplifier has a gain of 102 d B, a phase margin of 52.8°, a gain-bandwidth product of 4.41 MHz and a power of 43 μW. The total compensation capacitors are equal to 1.13 p F and 1.03 p F. The better figures-of-merits are 108 750 and 205 113(MHz×p F/m W). The layout areas are 0.064 mm×0.026 mm and 0.063 mm×0.027 mm. Compared with the CFCC scheme, the gainbandwidth product is extended by 1.6 times at CL=500 p F and Ca=1.1 p F.展开更多
文摘Objective To develop a universal quantitative immunoenzyme assay (EIA) for detecting amplified products of nucleic acid and its application in hepatit is C virus (HCV). Methods The appropriate cycle number of amplification was selected to s top polymerase chain reaction (PCR) before the “plateau stage”. At the same ti me, primers HCV(3) of the second PCR were modified with biotin so that the ampli fied products were labeled. The products were diluted and subsequently added t o the streptavidin coated wells, and the biotinylated products were captured, f ollowed by denaturation of NaOH, and non biotinylated strands were removed. Hy bridization was performed by adding the specific probe labeled with fluorescein. Finally anti fluorescein horse radish peroxidase (HRP) conjugates were added, after washing, 3,3',5,5', tetramethylbenzidine (TMB) was added to the well s and then measured on a microplate reader. Results EIA detection of amplified products of HCV showed that this ass ay was rapid, sensitive, specific and accurate. Correlation between the initial number of viral template and the EIA of amplified products was good. We also pro spectively investigated the response to interferon in five patients with HCV coi nfection. Results showed that this assay could be used as a guidance to the clin ical therapy in directing the use of antiviral drugs. Conclusions This assay could be widely used as a universal technique fo r the quantitative detection of amplified products of all nucleic acid (such as virus, bacterium) and other human genes (such as HLA B 27 ), it has vast vistas.
基金Supported by the Tianjin Science and Technology Project(No.13ZCZDGX02000)
文摘A low-power three-stage amplifier for driving large capacitive load is proposed. The feedback path formed by the active-feedback Miller capacitor leads to a high frequency complex-pole but a high Q-value, which significantly deteriorates the stability of the amplifier. The serial RC stage introduced as the second stage output load can optimize the resistor Rz and the capacitor Cz under fixed power and small compensation capacitor Ca, which brings about a suitable Q-value of the complex-pole and the gain-bandwidth product extension of the amplifier. The amplifiers were designed and implemented in a standard 65 nm CMOS process with capacitive loads of 500 p F and 2 n F, respectively. The post-layout simulation results show that the amplifier driving the 500 p F capacitive load can achieve a gain of 113 d B, a phase margin of 50.6° and a gain-bandwidth product of 5.22 MHz while consuming 24 μW from a 1.2 V supply. For the 2 n F capacitive load, the amplifier has a gain of 102 d B, a phase margin of 52.8°, a gain-bandwidth product of 4.41 MHz and a power of 43 μW. The total compensation capacitors are equal to 1.13 p F and 1.03 p F. The better figures-of-merits are 108 750 and 205 113(MHz×p F/m W). The layout areas are 0.064 mm×0.026 mm and 0.063 mm×0.027 mm. Compared with the CFCC scheme, the gainbandwidth product is extended by 1.6 times at CL=500 p F and Ca=1.1 p F.
