A fast-locking, low-jitter, phase-locked loop （PLL） with a simple phase-frequency detector is proposed. The phase-frequency detector is composed of only two XOR gates. It simultaneously achieves low jitter and short...A fast-locking, low-jitter, phase-locked loop （PLL） with a simple phase-frequency detector is proposed. The phase-frequency detector is composed of only two XOR gates. It simultaneously achieves low jitter and short locking time. The voltage-controlled oscillator within the PLL consists of four-stage ring oscillators which are coupled to each other and oscillate with the same frequency and a phase shift of 45. The PLL is fabricated in 0. 1Stem CMOS technology. The measured phase noise of the PLL output at 500kHz offset from the 5GHz center frequency is - 102.6dBc/Hz. The circuit exhibits a capture range of 280MHz and a low RMS jitter of 2.06ps. The power dissipation excluding the output buffers is only 21.6roW at a 1.8V supply.展开更多
The design of a 2. 488 Gbit/s clock and data recovery （CDR） If for synchronous digital hierarchy （SDH） STM-16 receiver is described. Based on the injected phase-locked loop （IPLL） and D-flip flop architectures, ...The design of a 2. 488 Gbit/s clock and data recovery （CDR） If for synchronous digital hierarchy （SDH） STM-16 receiver is described. Based on the injected phase-locked loop （IPLL） and D-flip flop architectures, the CDR IC was implemented in a standard 0. 35 μan complementary metal-oxide-semiconductor （CMOS） technology. With 2^31 -1 pseudorandom bit sequences （PRBS） input, the sensitivity of data recovery circuit is less than 20 mV with 10^-12 bit error rate （BER）. The recovered clock shows a root mean square （rms） jitter of 2. 8 ps and a phase noise of - 110 dBc/Hz at 100 kHz offset. The capture range of the circuit is larger than 40 MHz. With a 5 V supply, the circuit consumes 680 mW and the chip area is 1.49 mm × 1 mm.展开更多
A 2.5Gb/s clock and data recovery （CDR） circuit is designed and realized in TSMC＇s standard 0.18/μm CMOS process. The clock recovery is based on a PLL. For phase noise optimization,a dynamic phase and frequency de...A 2.5Gb/s clock and data recovery （CDR） circuit is designed and realized in TSMC＇s standard 0.18/μm CMOS process. The clock recovery is based on a PLL. For phase noise optimization,a dynamic phase and frequency detector （PFD） is used in the PLL. The rms jitter of the recovered 2.5GHz clock is 2.4ps and the SSB phase noise is - 111dBc/Hz at 10kHz offset. The rms jitter of the recovered 2.5Gb/s data is 3.3ps. The power consumption is 120mW.展开更多
Oscillator IC technique is developed by combining injecting synchronization technique with a ring VCO.Using the technique,a novel 2 488GHz of monolithical integrated injected synchronized ring VCO (ISRVCO) is realize...Oscillator IC technique is developed by combining injecting synchronization technique with a ring VCO.Using the technique,a novel 2 488GHz of monolithical integrated injected synchronized ring VCO (ISRVCO) is realized in a standard 0 25μm CMOS process.The ISRVCO is characterized by the following performances: -100dBc /Hz@1MHz at free running frequency,-91 7dBc/Hz@10kHz when injection is locked.With the 3 3V of power supply,the tuning range is 150MHz and the locking range is 100MHz with 50m V p p signal injection.展开更多
By jitter performance comparison between PLL (Phase Locked Loop) and DLL (Delay Locked Loop),a helpful equation is derived for the structure choice between DLL and PLL based synthesizers fabricated in CMOS processes ...By jitter performance comparison between PLL (Phase Locked Loop) and DLL (Delay Locked Loop),a helpful equation is derived for the structure choice between DLL and PLL based synthesizers fabricated in CMOS processes to get an optimum jitter performance and power consumption.For a frequency synthesizer,a large multiple factor prefers PLL based configuration which consumes less power,while a small one needs DLL based topology which produces a better jitter performance.展开更多
AIM: To determine whether lentivirus-mediated shRNA targeting the X-linked inhibitor of apoptosis protein (XIAP) gene could be exploited in the treatment of pancreatic cancer. METHODS: Human pancreatic cancer cells Pa...AIM: To determine whether lentivirus-mediated shRNA targeting the X-linked inhibitor of apoptosis protein (XIAP) gene could be exploited in the treatment of pancreatic cancer. METHODS: Human pancreatic cancer cells Panc-1, Mia-paca2, Bxpc-3 and SW1990, infected with lentivirus, were analyzed by real-time polymerase chain reaction (PCR). Western blotting was used to examine XIAP protein levels, survivin and p-Akt to confirm the result of real-time PCR and determine the possible mechanism. The 3-(4,5-cimethylthiazol-2-yl)-2,5- diphenyl tetrazolium bromide (MTT) assay was used to measure IC50 to determine chemosensitivity to the chemotherapeutic drugs 5-fluorouracil (5-FU) and gemcitabine. A colony assay, MTT assay and a tumorigenicity experiment were used to study cell proliferation in vitro and in vivo . Caspase-3/7 activity, 4',6-diamidino-2-phenylindole-staining and flow cytometric measurements were used to study apoptosis in SW1990 cells. RESULTS: XIAP proteins were found to be differen- tially expressed among pancreatic cancer cell lines Panc-1, Mia-paca2, Bxpc-3 and SW1990. Data of real-time PCR and Western blotting showed that XIAP was reduced persistently and markedly by lentivirus-mediated shRNA. Downregulation of XIAP by transfection with XIAP shRNA resulted in decreased p-Akt expression. XIAP shRNA also inhibited the growth of pancreatic cancer cells in vitro and in vivo , enhanced drug-induced apoptosis and increased chemosensitivity to 5-FU and gemcitabine. Results also suggest that inhibition of XIAP and subsequent p-Akt depletion may have an anti-tumor effect through attenuating the ability of cancer cells to survive. CONCLUSION: Lentivirus-mediated gene therapy is an attractive strategy in the treatment of pancreatic cancer and justifies the use of lentivirus in pancreatic cancer gene therapy studies.展开更多
Synchronous sampling is very essential in underwater multilinear array seismic exploration system in which every acquisition node(AN)samples analog signals by its own analog-digital converter(ADC).Aiming at the proble...Synchronous sampling is very essential in underwater multilinear array seismic exploration system in which every acquisition node(AN)samples analog signals by its own analog-digital converter(ADC).Aiming at the problems of complex synchronous sampling method and long locking time after varying sampling rate in traditional underwater seismic exploration system,an improved synchronous sampling model based on the master-slave synchronous model and local clock asynchronous drive with non phase locked loop(PLL)is built,and a high-precision synchronous sampling method is proposed,which combines the short-term stability of local asynchronous driving clock with the master-slave synchronous calibration of local sampling clock.Based on the improved synchronous sampling model,the influence of clock stability,transmission delay and phase jitter on synchronous sampling error is analyzed,and a high-precision calibration method of synchronous sampling error based on step-by-step compensation of transmission delay is proposed.The model and method effectively realize the immunity of phase jitter on synchronous sampling error in principle,and compensate the influence of signal transmission delay on synchronous sampling error.At the same time,it greatly reduces the complexity of software and hardware implementation of synchronous sampling,and solves the problem of long locking time after changing the sampling rate in traditional methods.The experimental system of synchronous sampling for dual linear array is built,and the synchronous sampling accuracy is better than 5 ns.展开更多
In underground mining, machine design is predominantly dictated by mine conditions and individual customer desires. In partnership with Foresight Energy, J. H. Fletcher & Company was tasked to design and manufactu...In underground mining, machine design is predominantly dictated by mine conditions and individual customer desires. In partnership with Foresight Energy, J. H. Fletcher & Company was tasked to design and manufacture a new roof bolting machine with six independent drilling apparatus on board capable of drilling and bolting the roof and ribs with material handling. The objective was to produce a machine capable of drilling and installing six bolts simultaneously with a limited number of operators. The goal of the mine is to decrease the time to bolt a cut to improve the safety level of the current roof bolting method, improve efficiency and to improve the bottom line cost of entry development. The customer wanted four drills at the front of the machine dedicated to installing roof bolts and then another two drills behind them dedicated to rib bolts. This dictated the requirement of latched controls, which would allow the operator to start drilling one hole and then latch the controls to be able to move on to the next.The result of the design is a machine with a single platform and six independent masts with drillheads:four masts strictly for drilling and installing roof bolts on the front of the platform and two masts on the back of the platform for rib bolts. The controls at each operator's station include a latch control for drilling. The six-head roof bolter allows fewer operators to drill and install roof and rib bolts, which in turn lowers the miners' roof exposure per cut. This design reduces the operator's exposure from the inherent pinch points and rotary hazards once he has engaged the latch drilling. Therefore, the machine will help to decrease the time to bolt a cut, improving productivity while enhancing the ability to operate the machine safely.展开更多
A monolithic clock-recovery circuit used in 622 Mb/s optical communication system is designed,which is based on the phase-locked loop theory,and uses bipolar transistor model.It overcomes the shortcoming of clock reco...A monolithic clock-recovery circuit used in 622 Mb/s optical communication system is designed,which is based on the phase-locked loop theory,and uses bipolar transistor model.It overcomes the shortcoming of clock recovery method based on filter,and implements monolithic clock-recovery IC.The designed circuits include phase detector,voltage-controlled oscillator and loop filter.Among them,the voltage-control oscillator is a modified two-stage ring oscillator,which provides quadrature clock signals and presents wide voltage-controlled range and high voltage-controlling sensitivity.展开更多
Insight problem solving is characterized by mental impasses,states of mind in which the problem solver does not know what to do next.Although many studies have investigated the neural correlates of insight problem sol...Insight problem solving is characterized by mental impasses,states of mind in which the problem solver does not know what to do next.Although many studies have investigated the neural correlates of insight problem solving,however,the question when mental impasses occur during insight problem solving has been rarely studied.The present study adopted high temporal resolution ERPs to investigate the temporal dynamics of an impasse underlying insight problem solving.Time locked ERPs were recorded associated with problems with impasses(PWI) and problems without impasses(POI).The problem types were determined by participants' subjective responses.The results revealed an early frontocentral P2 was linked with the preconscious awareness of mental impasses and a P3a was associated with fixed attention when the impasse formed.These findings suggest the impasse may occur initially at a relatively early stage and metacognition plays an important role in insight problem solving.展开更多
Objective: OCT4A has been known to play a critical role in the maintenance of pluripotency of embryonic stem cells. Recent research has shown that OCT4A is also expressed in partial tumor cell lines and tissues. This ...Objective: OCT4A has been known to play a critical role in the maintenance of pluripotency of embryonic stem cells. Recent research has shown that OCT4A is also expressed in partial tumor cell lines and tissues. This study is aimed to develop a real-time reverse transcriptase polymerase chain reaction (RT-PCR) assay for relative quantitative detection of OCT4A mRNA and discrimination from OCT4B, pseudogene, and genomic contaminations. Methods: A locked nucleic acid (LNA)-modified probe was designed to discern the single base difference 352A/C to identify OCT4A mRNA. An exon-junction primer was designed to avoid false positive caused by genomic contaminations. In addition, a house keeping gene glyceraldehyde-3-phosphate dehydrogenase (GAPDH) was measured in parallel to normalize the differences between samples and operations. Results: Experiments showed that the newly established RT-PCR assay amplified the OCT4A mRNA selectively; OCT4A analogues gave negative signals. Cell lines nTERA-2 and HepG2 showed positive results in OCT4A expression, while for HeLa and 293 cell lines, as well as primary peripheral blood mononuclear cells (PBMCs), OCT4A expression was negative. Additionally, the relative quantity of OCT4A mRNA was calculated by cycle threshold (Ct) method and house keeping gene normalization. Conclusions: This technique proved to be effective for relative quantitation of OCT4A mRNA with high specificity.展开更多
Purpose： To describe our clinical experience with a system named SureShorTM Distal Targeting （Smith ＆ Nephew, Memphis, USA） based on magnetic field presence and discuss our suggestions on this technique. Methods：...Purpose： To describe our clinical experience with a system named SureShorTM Distal Targeting （Smith ＆ Nephew, Memphis, USA） based on magnetic field presence and discuss our suggestions on this technique. Methods： We analysed prospectively 47 patients affected by humeral, tibial or femoral fractures, treated in our institution during a 3-year period of time （August 2010 to September 2013）. We considered the following parameters： the time to set up, the time to position a single screw, the effectiveness of the system （drilling ad screwing）, the irradiation exposure time during distal locking procedure and surgical complications. Results： A total number of 96 screws were inserted. The mean preparation time of the device was 5.1 min _＋ 2 min （range 3 10 min）. The mean time for single screw targeting was 5.8 min ± 2.3 min （range 4-18 min）. No major complications occurred. Only a few locking procedures were needed to be practiced in order to obtain the required expertise with this targeting device. Conclusion： According to our results, this device is reliable and valid whenever the correct technique is followed. It is also user friendly, exposes to lower radiation and needs less surgical time compared to relative data from the literature. However, the surgeon should always be aware of how to use the free hand technique in case of malfunctioning of the system.展开更多
文摘A fast-locking, low-jitter, phase-locked loop （PLL） with a simple phase-frequency detector is proposed. The phase-frequency detector is composed of only two XOR gates. It simultaneously achieves low jitter and short locking time. The voltage-controlled oscillator within the PLL consists of four-stage ring oscillators which are coupled to each other and oscillate with the same frequency and a phase shift of 45. The PLL is fabricated in 0. 1Stem CMOS technology. The measured phase noise of the PLL output at 500kHz offset from the 5GHz center frequency is - 102.6dBc/Hz. The circuit exhibits a capture range of 280MHz and a low RMS jitter of 2.06ps. The power dissipation excluding the output buffers is only 21.6roW at a 1.8V supply.
文摘The design of a 2. 488 Gbit/s clock and data recovery （CDR） If for synchronous digital hierarchy （SDH） STM-16 receiver is described. Based on the injected phase-locked loop （IPLL） and D-flip flop architectures, the CDR IC was implemented in a standard 0. 35 μan complementary metal-oxide-semiconductor （CMOS） technology. With 2^31 -1 pseudorandom bit sequences （PRBS） input, the sensitivity of data recovery circuit is less than 20 mV with 10^-12 bit error rate （BER）. The recovered clock shows a root mean square （rms） jitter of 2. 8 ps and a phase noise of - 110 dBc/Hz at 100 kHz offset. The capture range of the circuit is larger than 40 MHz. With a 5 V supply, the circuit consumes 680 mW and the chip area is 1.49 mm × 1 mm.
文摘A 2.5Gb/s clock and data recovery （CDR） circuit is designed and realized in TSMC＇s standard 0.18/μm CMOS process. The clock recovery is based on a PLL. For phase noise optimization,a dynamic phase and frequency detector （PFD） is used in the PLL. The rms jitter of the recovered 2.5GHz clock is 2.4ps and the SSB phase noise is - 111dBc/Hz at 10kHz offset. The rms jitter of the recovered 2.5Gb/s data is 3.3ps. The power consumption is 120mW.
文摘Oscillator IC technique is developed by combining injecting synchronization technique with a ring VCO.Using the technique,a novel 2 488GHz of monolithical integrated injected synchronized ring VCO (ISRVCO) is realized in a standard 0 25μm CMOS process.The ISRVCO is characterized by the following performances: -100dBc /Hz@1MHz at free running frequency,-91 7dBc/Hz@10kHz when injection is locked.With the 3 3V of power supply,the tuning range is 150MHz and the locking range is 100MHz with 50m V p p signal injection.
文摘By jitter performance comparison between PLL (Phase Locked Loop) and DLL (Delay Locked Loop),a helpful equation is derived for the structure choice between DLL and PLL based synthesizers fabricated in CMOS processes to get an optimum jitter performance and power consumption.For a frequency synthesizer,a large multiple factor prefers PLL based configuration which consumes less power,while a small one needs DLL based topology which produces a better jitter performance.
基金Supported by National Natural Science Foundation of China,No. 30872492Natural Science Foundation of Hunan Province, No. 088JJ3042
文摘AIM: To determine whether lentivirus-mediated shRNA targeting the X-linked inhibitor of apoptosis protein (XIAP) gene could be exploited in the treatment of pancreatic cancer. METHODS: Human pancreatic cancer cells Panc-1, Mia-paca2, Bxpc-3 and SW1990, infected with lentivirus, were analyzed by real-time polymerase chain reaction (PCR). Western blotting was used to examine XIAP protein levels, survivin and p-Akt to confirm the result of real-time PCR and determine the possible mechanism. The 3-(4,5-cimethylthiazol-2-yl)-2,5- diphenyl tetrazolium bromide (MTT) assay was used to measure IC50 to determine chemosensitivity to the chemotherapeutic drugs 5-fluorouracil (5-FU) and gemcitabine. A colony assay, MTT assay and a tumorigenicity experiment were used to study cell proliferation in vitro and in vivo . Caspase-3/7 activity, 4',6-diamidino-2-phenylindole-staining and flow cytometric measurements were used to study apoptosis in SW1990 cells. RESULTS: XIAP proteins were found to be differen- tially expressed among pancreatic cancer cell lines Panc-1, Mia-paca2, Bxpc-3 and SW1990. Data of real-time PCR and Western blotting showed that XIAP was reduced persistently and markedly by lentivirus-mediated shRNA. Downregulation of XIAP by transfection with XIAP shRNA resulted in decreased p-Akt expression. XIAP shRNA also inhibited the growth of pancreatic cancer cells in vitro and in vivo , enhanced drug-induced apoptosis and increased chemosensitivity to 5-FU and gemcitabine. Results also suggest that inhibition of XIAP and subsequent p-Akt depletion may have an anti-tumor effect through attenuating the ability of cancer cells to survive. CONCLUSION: Lentivirus-mediated gene therapy is an attractive strategy in the treatment of pancreatic cancer and justifies the use of lentivirus in pancreatic cancer gene therapy studies.
基金National Key Research and Development Program of China(No.2018YFE0208200)National Natural Science Foundation of China(Nos.61971307,61905175,51775377)+5 种基金National Key Research and Development Plan Project(No.2020YFB2010800)The Fok Ying Tung Education Foundation(No.171055)China Postdoctoral Science Foundation(No.2020M680878)Guangdong Province Key Research and Development Plan Project(No.2020B0404030001)Tianjin Science and Technology Plan Project(No.20YDTPJC01660)Project of Foreign Affairs Committee of China Aviation Development Sichuan Gas Turbine Research Institute(Nos.GJCZ-2020-0040,GJCZ-2020-0041)。
文摘Synchronous sampling is very essential in underwater multilinear array seismic exploration system in which every acquisition node(AN)samples analog signals by its own analog-digital converter(ADC).Aiming at the problems of complex synchronous sampling method and long locking time after varying sampling rate in traditional underwater seismic exploration system,an improved synchronous sampling model based on the master-slave synchronous model and local clock asynchronous drive with non phase locked loop(PLL)is built,and a high-precision synchronous sampling method is proposed,which combines the short-term stability of local asynchronous driving clock with the master-slave synchronous calibration of local sampling clock.Based on the improved synchronous sampling model,the influence of clock stability,transmission delay and phase jitter on synchronous sampling error is analyzed,and a high-precision calibration method of synchronous sampling error based on step-by-step compensation of transmission delay is proposed.The model and method effectively realize the immunity of phase jitter on synchronous sampling error in principle,and compensate the influence of signal transmission delay on synchronous sampling error.At the same time,it greatly reduces the complexity of software and hardware implementation of synchronous sampling,and solves the problem of long locking time after changing the sampling rate in traditional methods.The experimental system of synchronous sampling for dual linear array is built,and the synchronous sampling accuracy is better than 5 ns.
文摘In underground mining, machine design is predominantly dictated by mine conditions and individual customer desires. In partnership with Foresight Energy, J. H. Fletcher & Company was tasked to design and manufacture a new roof bolting machine with six independent drilling apparatus on board capable of drilling and bolting the roof and ribs with material handling. The objective was to produce a machine capable of drilling and installing six bolts simultaneously with a limited number of operators. The goal of the mine is to decrease the time to bolt a cut to improve the safety level of the current roof bolting method, improve efficiency and to improve the bottom line cost of entry development. The customer wanted four drills at the front of the machine dedicated to installing roof bolts and then another two drills behind them dedicated to rib bolts. This dictated the requirement of latched controls, which would allow the operator to start drilling one hole and then latch the controls to be able to move on to the next.The result of the design is a machine with a single platform and six independent masts with drillheads:four masts strictly for drilling and installing roof bolts on the front of the platform and two masts on the back of the platform for rib bolts. The controls at each operator's station include a latch control for drilling. The six-head roof bolter allows fewer operators to drill and install roof and rib bolts, which in turn lowers the miners' roof exposure per cut. This design reduces the operator's exposure from the inherent pinch points and rotary hazards once he has engaged the latch drilling. Therefore, the machine will help to decrease the time to bolt a cut, improving productivity while enhancing the ability to operate the machine safely.
文摘A monolithic clock-recovery circuit used in 622 Mb/s optical communication system is designed,which is based on the phase-locked loop theory,and uses bipolar transistor model.It overcomes the shortcoming of clock recovery method based on filter,and implements monolithic clock-recovery IC.The designed circuits include phase detector,voltage-controlled oscillator and loop filter.Among them,the voltage-control oscillator is a modified two-stage ring oscillator,which provides quadrature clock signals and presents wide voltage-controlled range and high voltage-controlling sensitivity.
基金supported by the National Basic Research Program of China (2010CB833904)Research Innovation Program for College Graduates of Jiangsu Province (CXLX12_0353, CXLX12_0351)the Fourth High-level Personnel Training Project in Jiangsu Province
文摘Insight problem solving is characterized by mental impasses,states of mind in which the problem solver does not know what to do next.Although many studies have investigated the neural correlates of insight problem solving,however,the question when mental impasses occur during insight problem solving has been rarely studied.The present study adopted high temporal resolution ERPs to investigate the temporal dynamics of an impasse underlying insight problem solving.Time locked ERPs were recorded associated with problems with impasses(PWI) and problems without impasses(POI).The problem types were determined by participants' subjective responses.The results revealed an early frontocentral P2 was linked with the preconscious awareness of mental impasses and a P3a was associated with fixed attention when the impasse formed.These findings suggest the impasse may occur initially at a relatively early stage and metacognition plays an important role in insight problem solving.
基金Project (No. 2010036) supported by the program of "Medical Healthcare and Scientific Study" of the Ministry of Health,Inner Mongolia,China
文摘Objective: OCT4A has been known to play a critical role in the maintenance of pluripotency of embryonic stem cells. Recent research has shown that OCT4A is also expressed in partial tumor cell lines and tissues. This study is aimed to develop a real-time reverse transcriptase polymerase chain reaction (RT-PCR) assay for relative quantitative detection of OCT4A mRNA and discrimination from OCT4B, pseudogene, and genomic contaminations. Methods: A locked nucleic acid (LNA)-modified probe was designed to discern the single base difference 352A/C to identify OCT4A mRNA. An exon-junction primer was designed to avoid false positive caused by genomic contaminations. In addition, a house keeping gene glyceraldehyde-3-phosphate dehydrogenase (GAPDH) was measured in parallel to normalize the differences between samples and operations. Results: Experiments showed that the newly established RT-PCR assay amplified the OCT4A mRNA selectively; OCT4A analogues gave negative signals. Cell lines nTERA-2 and HepG2 showed positive results in OCT4A expression, while for HeLa and 293 cell lines, as well as primary peripheral blood mononuclear cells (PBMCs), OCT4A expression was negative. Additionally, the relative quantity of OCT4A mRNA was calculated by cycle threshold (Ct) method and house keeping gene normalization. Conclusions: This technique proved to be effective for relative quantitation of OCT4A mRNA with high specificity.
文摘Purpose： To describe our clinical experience with a system named SureShorTM Distal Targeting （Smith ＆ Nephew, Memphis, USA） based on magnetic field presence and discuss our suggestions on this technique. Methods： We analysed prospectively 47 patients affected by humeral, tibial or femoral fractures, treated in our institution during a 3-year period of time （August 2010 to September 2013）. We considered the following parameters： the time to set up, the time to position a single screw, the effectiveness of the system （drilling ad screwing）, the irradiation exposure time during distal locking procedure and surgical complications. Results： A total number of 96 screws were inserted. The mean preparation time of the device was 5.1 min _＋ 2 min （range 3 10 min）. The mean time for single screw targeting was 5.8 min ± 2.3 min （range 4-18 min）. No major complications occurred. Only a few locking procedures were needed to be practiced in order to obtain the required expertise with this targeting device. Conclusion： According to our results, this device is reliable and valid whenever the correct technique is followed. It is also user friendly, exposes to lower radiation and needs less surgical time compared to relative data from the literature. However, the surgeon should always be aware of how to use the free hand technique in case of malfunctioning of the system.
