In this paper, we have demonstrated an Er-doped ultrafast laser with a single mode fiber-gradient index multimode fiber-single mode fiber(SMF-GIMF-SMF, SMS) structure as saturable absorber(SA), which can generate not ...In this paper, we have demonstrated an Er-doped ultrafast laser with a single mode fiber-gradient index multimode fiber-single mode fiber(SMF-GIMF-SMF, SMS) structure as saturable absorber(SA), which can generate not only stable single-pulse state, but also special mode-locked pulses with the characteristics of high energy and noisy behaviors at proper pump power and cavity polarization state. In addition, we have deeply investigated the real-time spectral evolutions of the mode-locked pulses through the dispersive Fourier transformation(DFT) technique. It can be found that the pulse regime can actually consist of a lot of small noise pulses with randomly varying intensities. We believe that these results will further enrich the nonlinear dynamical processes in the ultrafast lasers.展开更多
Synchronized dual-wavelength mode-locked laser is investigated numerically and experimentally in the normal dispersion regime.A programmable optical processor is introduced to shape the spectral profile and adjust the...Synchronized dual-wavelength mode-locked laser is investigated numerically and experimentally in the normal dispersion regime.A programmable optical processor is introduced to shape the spectral profile and adjust the net dispersion,which is demonstrated be a convenient and reliable approach to generate dual-color solitons.The time-stretch dispersive Fourier transform and frequency-resolved optical grating techniques are utilized to measure the spectral and temporal characteristics of dual-color solitons,respectively.The numerical results are consistent with experimental results.This work may facilitate the development of filter-based mode-locked laser and the understanding of multi-wavelength soliton dynamics.展开更多
Based on the scatter matrix of the four-port lossless mismatched circulator, the phase differential equation of the injection-locked magnetron is derived by comparing different effects of the mismatched and perfect ci...Based on the scatter matrix of the four-port lossless mismatched circulator, the phase differential equation of the injection-locked magnetron is derived by comparing different effects of the mismatched and perfect circulator on the injection ratio. Besides, the locking range of the injection-locked magnetron with the mismatched circulator is deduced by functional operation. In addition, the phase differential equation and the locked bandwidth of the injection-locked system with a mismatched circulator are compared with those of the small injection-ratio case with a perfect circulator. The in- fluence of the circulator reflection coefficient on the injection-locked magnetron is also analyzed by numerical calculation. Theoretical analysis shows that the decrement of the locked bandwidth is less than 1% and decrement of the stable phase difference is less than 1.2% when the reflection coefficient is less than 0.1.展开更多
Despite extensive investigations,no precursor patterns for reliably predicting major earthquakes have thus far been identified.Seismogenic locked segments that can accumulate adequate strain energy to cause major eart...Despite extensive investigations,no precursor patterns for reliably predicting major earthquakes have thus far been identified.Seismogenic locked segments that can accumulate adequate strain energy to cause major earthquakes are highly heterogeneous and low brittle.The progressive cracking of the locked segments with these properties can produce an interesting seismic phenomenon:a landmark earthquake and a sequence of smaller subsequent earthquakes(pre-shocks)always arise prior to another landmark earthquake within a well-defined seismic zone and its current seismic period.Applying a mechanical model,magnitude constraint conditions,and case study data of 62 worldwide seismic zones,we show that two adjacent landmark earthquakes reliably occur at the volume-expansion point and peak-stress point(rupture)of a locked segment;thus,the former is an identified precursor for the latter.Such a precursor seismicity pattern before the locked-segment rupture has definite physical meanings,and it is universal regardless of the focal depth.Because the evolution of landmark earthquakes follows a deterministic rule described by the model,they are predictable.The results of this study lay a firm physical foundation for reliably predicting the occurrence of future landmark earthquakes in a seismic zone and can greatly improve our understanding of earthquake generation mechanism.展开更多
AIM To assess the antiviral effects of hepatitis B virus(HBV) S gene-specific anti-gene locked nucleic acid(LNA) in transgenic mice.METHODS Thirty HBV transgenic mice were acclimatized to laboratory conditions and pos...AIM To assess the antiviral effects of hepatitis B virus(HBV) S gene-specific anti-gene locked nucleic acid(LNA) in transgenic mice.METHODS Thirty HBV transgenic mice were acclimatized to laboratory conditions and positive for serum HBV surface antigen(HBs Ag) and HBV DNA, were randomly divided into 5 groups(n = 7), including negative control(blank control, unrelated sequence control), positive control(lamivudine, anti-sense-LNA), and anti-gene-LNA experimental group. LNA was injected into transgenic mice by tail vein while lamivudine was administeredby gavage. Serum HBV DNA and HBs Ag levels were determined by fluorescence-based PCR and enzymelinked immune sorbent assay, respectively. HBV S gene expression amounts were assessed by reverse transcription polymerase chain reaction. Positive rates of HBsA g in liver cells were evaluated immunohistochemistry.RESULTS Average rate reductions of HBs Ag after treatment on the 3 rd, 5 th, and 7 th days were 32.34%, 45.96%, and 59.15%, respectively. The inhibitory effect of antigene-LNA on serum HBs Ag peaked on day 7, with statistically significant differences compared with pretreatment(0.96 ± 0.18 vs 2.35 ± 0.33, P < 0.05) and control values(P < 0.05 for all). Average reduction rates of HBV DNA on the 3 rd, 5 th, and 7 th days were 38.55%, 50.95%, and 62.26%, respectively. This inhibitory effect peaked on the 7 th day after treatment with anti-gene-LNA, with statistically significant differences compared with pre-treatment(4.17 ± 1.29 vs 11.05 ± 1.25, P < 0.05) and control values(P < 0.05 for all). The mR NA levels of the HBV S gene(P < 0.05 for all) and rates of HBsA g positive liver cells(P < 0.05 for all) were significantly reduced compared with the control groups. Liver and kidney function, and histology showed no abnormalities. CONCLUSION Anti-gene-LNA targeting the S gene of HBV displays strong inhibitory effects on HBV in transgenic mice, providing theoretical and experimental bases for gene therapy in HBV.展开更多
Locked segments are recognized as a critical role that controls the stability of rock slopes but remain an unclear and challenging problem with respect to their role incorporated into the failure mechanism.In order to...Locked segments are recognized as a critical role that controls the stability of rock slopes but remain an unclear and challenging problem with respect to their role incorporated into the failure mechanism.In order to study the effect of the locked segments on the initial failure process of rockslides,thirty-six groups of locked segment specimens with three different lithologies were prepared,direct shear tests were carried out to obtain the accelerations caused by brittle failure of the locked segment specimens.Experiment results showed that the maximum accelerations caused by the brittle failure of locked segment specimens was 2.91 g in the horizontal direction,and 3.18 g in the vertical direction.We took the Wangjiayan rockslide in 2008 Wenchuan earthquake as an example,the critical balance condition of the sliding mass under combined effect of gravity and accelerations induced by brittle failure of locked segment was analyzed,which indicated that the initial failure process of the Wangjiayan rockslides was notably influenced by the existence of the locked segment.The departure acceleration and direction of the Wangjiayan rockslide were proposed.The study results can provide a new insight into the understanding of the initial failure mechanism of rockslides with locked segments.展开更多
The effects of externally applied resonant magnetic perturbation (RMP) on the locked mode of the neoclassical tearing mode (NTM) are numerically investigated by means of a set of reduced magnetohydrodynamic equations....The effects of externally applied resonant magnetic perturbation (RMP) on the locked mode of the neoclassical tearing mode (NTM) are numerically investigated by means of a set of reduced magnetohydrodynamic equations.It is found that,for a small bootstrap current fraction,three regimes,namely the slight suppression regime,the small locked island (SLI) regime and the big locked island (BLI) regime,are discovered with the increase of RMP strength.For a much higher bootstrap current fraction,however,a new oscillation regime appears instead of the SLI regime,although the other regimes still remain.The physical process in each regime is analyzed in detail based on the phase difference between the NTM and the RMP.Moreover,the critical values of the RMP in both SLI and BLI regimes are obtained,and their dependence on key plasma parameters is discussed as well.展开更多
Magnetohydrodynamic(MHD)instabilities are widely observed during tokamak plasma operation.Magnetic diagnostics provide important information which supports the understanding and control of MHD instabilities.This paper...Magnetohydrodynamic(MHD)instabilities are widely observed during tokamak plasma operation.Magnetic diagnostics provide important information which supports the understanding and control of MHD instabilities.This paper presents the current status of the magnetic diagnostics dedicated to measuring MHD instabilities at the J-TEXT tokamak;the diagnostics consist of five Mirnov probe arrays for measuring high-frequency magnetic perturbations and two saddle-loop arrays for low-frequency magnetic perturbations,such as the locked mode.In recent years,several changes have been made to these arrays.The structure of the probes in the poloidal Mirnov arrays has been optimized to improve their mechanical strength,and the number of in-vessel saddle loops has also been improved to support better spatial resolution.Due to the installation of high-field-side(HFS)divertor targets in early 2019,some of the probes were removed,but an HFS Mirnov array was designed and installed behind the targets.Owing to its excellent toroidal symmetry,the HFS Mirnov array has,for the first time at J-TEXT,provided valuable new information about the locked mode and the quasi-static mode(QSM)in the HFS.Besides,various groups of magnetic diagnostics at different poloidal locations have been systematically used to measure the QSM,which confirmed the poloidal mode number m and the helical structure of the QSM.By including the HFS information,the 2/1 resonant magnetic perturbation(RMP)-induced locked mode was measured to have a poloidal mode number m of~2.展开更多
Aim. Comparison of the trascranial Doppler (TCD) characteristics of cerebral circulation in persistent vegetative status (PVS), locked in syndrome and brain death patients. Methods. Using ...Aim. Comparison of the trascranial Doppler (TCD) characteristics of cerebral circulation in persistent vegetative status (PVS), locked in syndrome and brain death patients. Methods. Using TCD ultrasound to detect the flow velocity and waveform patterns of middle cerebral artery (MCA) and basilar artery (BA) in patients with PVS, locked in syndrome and brain death. Results. The mean velocities of middle cerebral artery (Vmca) and basilar artery (Vba) were 30.0cm/s and 24.3cm/s in PVS patients respectively, which decreased 45.0% and 14.4% in comparing with normal value. For patients with locked in syndrome, Vmca and Vba were 49.7cm/s and 9.8cm/s, which decreased 5.0% and 61.7% than the normal value respectively. These results showed that the decrease of anterior circulation was predominant in PVS, and the decrease of posterior circulation was predominant in locked in syndrome. A unique diastolic reverse flow, short peak systolic wave or undetectable flow signal in middle cerebral artery were predominant in brain death patients, which was completely different from that of either PVS or locked in syndrome. Conclusion. TCD was a valuable tool in distinguishing PVS, locked in syndrome and brain death patients according to the differences in velocities and patterns of anterior and posterior cerebral arteries.展开更多
We report an efficient continuous-wave self-Raman laser at 1176 nm based on a 20-mm-long composite YVO4/Nd：YVO4/YVO4 crystal and pumped by a wavelength-locked 878.9 nm diode laser.A maximum output power of 5.3 W is a...We report an efficient continuous-wave self-Raman laser at 1176 nm based on a 20-mm-long composite YVO4/Nd：YVO4/YVO4 crystal and pumped by a wavelength-locked 878.9 nm diode laser.A maximum output power of 5.3 W is achieved at a pump power of 26 W,corresponding to an optical conversion efficiency of 20%and a slope efficiency of 21%.The Raman threshold for the diode pump power was only 0.92 W.The results reveal that in-band pumping by a wavelength-locked diode laser significantly enhances output power and efficiency of self-Raman lasers by virtue of improved pump absorption and relieved thermal loading.展开更多
In deep space exploration,many engineering and scientific requirements require the accuracy of the measured Doppler frequency to be as high as possible.In our paper,we analyze the possible frequency measurement points...In deep space exploration,many engineering and scientific requirements require the accuracy of the measured Doppler frequency to be as high as possible.In our paper,we analyze the possible frequency measurement points of the third-order phase-locked loop(PLL)and find a new Doppler measurement strategy.Based on this finding,a Doppler frequency measurement algorithm with significantly higher measurement accuracy is obtained.In the actual data processing,compared with the existing engineering software,the accuracy of frequency of 1 second integration is about 5.5 times higher when using the new algorithm.The improved algorithm is simple and easy to implement.This improvement can be easily combined with other improvement methods of PLL,so that the performance of PLL can be further improved.展开更多
Applications using simultaneous wireless information and power transfer(SWIPT)have increased significantly.Wireless communication technologies can be combined with the Internet of Things to develop many innovative app...Applications using simultaneous wireless information and power transfer(SWIPT)have increased significantly.Wireless communication technologies can be combined with the Internet of Things to develop many innovative applications using SWIPT,which is mainly based on wireless energy harvesting from electromagnetic waves used in communications.Wireless power transfer that uses magnetrons has been developed for communication technologies.Injection-locked magnetrons that can be used to facilitate high-power SWIPT for several devices are reviewed in this paper.This new technology is expected to pave the way for promoting the application of SWIPT in a wide range of fields.展开更多
In this paper, a self-mode-locked Nd:YVO_4 picosecond vortex laser is demonstrated, which can operate on the different Laguerre-Gaussian(LG) modes at 1 064 nm. A π/2 mode converter is utilized to realize the picoseco...In this paper, a self-mode-locked Nd:YVO_4 picosecond vortex laser is demonstrated, which can operate on the different Laguerre-Gaussian(LG) modes at 1 064 nm. A π/2 mode converter is utilized to realize the picosecond vortex laser with LG mode transformed from the high-order Hermite-Gaussian(HG) mode. For the proposed laser, the mode-locked pulse repetition rate is 1.81 GHz. The average output powers of LG_(12) mode and LG_(02) mode are 1.241 W and 1.27 W, respectively, and their slope efficiencies are 23.2% and 24%, respectively.展开更多
Prediction of disruptions caused by locked modes using the Back-Propagation （BP） neural network is completed on J-TEXT tokamak. The network, which is based on the BP neural network, uses Mirnov coils and locked mode...Prediction of disruptions caused by locked modes using the Back-Propagation （BP） neural network is completed on J-TEXT tokamak. The network, which is based on the BP neural network, uses Mirnov coils and locked mode coils signals as input data, and outputs a signal including information of prediction of locked mode. The rate of successful prediction of locked modes is more than 90%. For intrinsic locked mode disruptions, the network can give a prewarning signal about 1 ms ahead of the locking-time. For the disruption caused by resonant magnetic perturbation （RMPs） locked modes, the network can give a prewarning signal about 10 ms ahead of the locking-time.展开更多
Circulating tumor DNA(ctDNA),carrying tumor-specific sequence mutations,is a promising biomarker for classification,diagnosis and prognosis of cancers.However,there is still a great challenge in discriminating single-...Circulating tumor DNA(ctDNA),carrying tumor-specific sequence mutations,is a promising biomarker for classification,diagnosis and prognosis of cancers.However,there is still a great challenge in discriminating single-base difference between ctDNA and its coexisting analogue(normal circulating DNA,ncDNA)at a serum sample.A locked nucleic acid(LNA)probe combined with a-HL nanopore sensor was designed,which achieved a high signal-to-background ratio(SBR)of^8.34 × 10^3,as well as a significant discrimination capability(~12.3 times)of single-base diffe rence.The accurate discrimination strategy is label-free,convenient,selective and sensitive,which has great potential in the early diagnosis of diseases and biomedical research fields.展开更多
BACKGROUND The presence of two distinct hepatitis B virus(HBV)Pol RT polymorphisms,rt269L and rt269I,could contribute to the unique clinical or virological phenotype of HBV genotype C2.Therefore,a simple and sensitive...BACKGROUND The presence of two distinct hepatitis B virus(HBV)Pol RT polymorphisms,rt269L and rt269I,could contribute to the unique clinical or virological phenotype of HBV genotype C2.Therefore,a simple and sensitive method capable of identifying both types in chronic hepatitis B(CHB)patients infected with genotype C2 should be developed.AIM To develop a novel simple and sensitive locked nucleic acid(LNA)-real timepolymerase chain reaction(RT-PCR)method capable of identifying two rt269 types in CHB genotype C2 patients.METHODS We designed proper primer and probe sets for LNA-RT-PCR for the separation of rt269 types.Using synthesized DNAs of the wild type and variant forms,melting temperature analysis,detection sensitivity,and endpoint genotyping for LNA-RT-PCR were performed.The developed LNA-RT-PCR method was applied to a total of 94 CHB patients of genotype C2 for the identification of two rt269 polymorphisms,and these results were compared with those obtained by a direct sequencing protocol.RESULTS The LNA-RT-PCR method could identify two rt269L and rt269I polymorphisms of three genotypes,two rt269L types[‘L1’(WT)and‘L2’]and one rt269I type(‘I’)in single(63 samples,72.4%)or mixed forms(24 samples,27.6%)in 87(92.6%sensitivity)of 94 samples from Korean CHB patients.When the results were compared with those obtained by the direct sequencing protocol,the LNA-RT-PCR method showed the same results in all but one of 87 positive detected samples(98.9%specificity).CONCLUSION The newly developed LNA-RT-PCR method could identify two rt269 polymorphisms,rt269L and rt269I,in CHB patients with genotype C2 infections.This method could be effectively used for the understanding of disease progression in genotype C2 endemic areas.展开更多
Considering the density dependence of quark mass, we investigate the phase transition between the （unpaired） strange quark matter and the color-flavor-locked matter, which are supposed to be two candidates for the g...Considering the density dependence of quark mass, we investigate the phase transition between the （unpaired） strange quark matter and the color-flavor-locked matter, which are supposed to be two candidates for the ground state of strongly interacting matter. We lind that if the current mass of strange quark m, is smmall, the strange quark matter remains stable unless the baryon density is very high. If m, is large, the phase transition from the strange quark matter to the color-flavor-locked matter in particular to its gapless phase is found to be different from the results predicted by previous works. A complicated phase diagram of three-flavor quark matter is presented, in which the color-flavor-locked phase region is suppressed for moderate densities.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
An injection-Locked divider(ILD)can provide good synchronization at lower inputsignal to noise ratio,which is its advantage over other types of divider.The general expressionof phase equation and equivalent model are ...An injection-Locked divider(ILD)can provide good synchronization at lower inputsignal to noise ratio,which is its advantage over other types of divider.The general expressionof phase equation and equivalent model are presented for the ILD with an input additive noise.In the absence of noise the performance of the phase-modulated signal through the ILD andsynchronous ranges of the ILD are given.The effects of the additive noise on the ILD arediscuued.The injection-locked amplifier(ILA)is only a particular case in which n=1,thereforethe given results arc applicable to the ILA.展开更多
基金supported by the Guangdong Basic and Applied Basic Research Foundation (No.2023A1515010093)the Shenzhen Fundamental Research Program (Stable Support Plan Program)(Nos.JCYJ20220809170611004, 20231121110828001 and 20231121113641002)the National Taipei University of Technology-Shenzhen University Joint Research Program (No.2024001)。
文摘In this paper, we have demonstrated an Er-doped ultrafast laser with a single mode fiber-gradient index multimode fiber-single mode fiber(SMF-GIMF-SMF, SMS) structure as saturable absorber(SA), which can generate not only stable single-pulse state, but also special mode-locked pulses with the characteristics of high energy and noisy behaviors at proper pump power and cavity polarization state. In addition, we have deeply investigated the real-time spectral evolutions of the mode-locked pulses through the dispersive Fourier transformation(DFT) technique. It can be found that the pulse regime can actually consist of a lot of small noise pulses with randomly varying intensities. We believe that these results will further enrich the nonlinear dynamical processes in the ultrafast lasers.
基金Project supported by the Innovation Program for Quantum Science and Technology(Grant No.2023ZD0301000)the National Natural Science Foundation of China(Grant Nos.12434018,62475073,1243000542,11621404,11561121003,11727812,61775059,12074122,62405090,62035005,and 11704123)+1 种基金the Natural Science Foundation of Shanghai(Grant No.23ZR1419000)China Postdoctoral Science Foundation(Grant Nos.2023M741188 and 2024T170275)。
文摘Synchronized dual-wavelength mode-locked laser is investigated numerically and experimentally in the normal dispersion regime.A programmable optical processor is introduced to shape the spectral profile and adjust the net dispersion,which is demonstrated be a convenient and reliable approach to generate dual-color solitons.The time-stretch dispersive Fourier transform and frequency-resolved optical grating techniques are utilized to measure the spectral and temporal characteristics of dual-color solitons,respectively.The numerical results are consistent with experimental results.This work may facilitate the development of filter-based mode-locked laser and the understanding of multi-wavelength soliton dynamics.
基金Project supported by the National Basic Research Program of China(Grant No.2013CB328901)the National Natural Science Foundation of China(Grant No.11305177)
文摘Based on the scatter matrix of the four-port lossless mismatched circulator, the phase differential equation of the injection-locked magnetron is derived by comparing different effects of the mismatched and perfect circulator on the injection ratio. Besides, the locking range of the injection-locked magnetron with the mismatched circulator is deduced by functional operation. In addition, the phase differential equation and the locked bandwidth of the injection-locked system with a mismatched circulator are compared with those of the small injection-ratio case with a perfect circulator. The in- fluence of the circulator reflection coefficient on the injection-locked magnetron is also analyzed by numerical calculation. Theoretical analysis shows that the decrement of the locked bandwidth is less than 1% and decrement of the stable phase difference is less than 1.2% when the reflection coefficient is less than 0.1.
基金supported by the National Key Research and Development Program of China (No. 2019YFC1509701)the Second Tibetan Plateau Scientific Expedition and Research Program (STEP) (No. 2019QZKK0904)+1 种基金the National Natural Science Foundation of China (No. 42107184)the China Postdoctoral Science Foundation (No. 2018M640181)
文摘Despite extensive investigations,no precursor patterns for reliably predicting major earthquakes have thus far been identified.Seismogenic locked segments that can accumulate adequate strain energy to cause major earthquakes are highly heterogeneous and low brittle.The progressive cracking of the locked segments with these properties can produce an interesting seismic phenomenon:a landmark earthquake and a sequence of smaller subsequent earthquakes(pre-shocks)always arise prior to another landmark earthquake within a well-defined seismic zone and its current seismic period.Applying a mechanical model,magnitude constraint conditions,and case study data of 62 worldwide seismic zones,we show that two adjacent landmark earthquakes reliably occur at the volume-expansion point and peak-stress point(rupture)of a locked segment;thus,the former is an identified precursor for the latter.Such a precursor seismicity pattern before the locked-segment rupture has definite physical meanings,and it is universal regardless of the focal depth.Because the evolution of landmark earthquakes follows a deterministic rule described by the model,they are predictable.The results of this study lay a firm physical foundation for reliably predicting the occurrence of future landmark earthquakes in a seismic zone and can greatly improve our understanding of earthquake generation mechanism.
基金Supported by National Natural Science Foundation of China,No.81460123Guangxi Graduate Innovation Program,No.201601005Guangxi Clinic Medicine Research Center of Hepatobiliary Disease,No.AD17129025
文摘AIM To assess the antiviral effects of hepatitis B virus(HBV) S gene-specific anti-gene locked nucleic acid(LNA) in transgenic mice.METHODS Thirty HBV transgenic mice were acclimatized to laboratory conditions and positive for serum HBV surface antigen(HBs Ag) and HBV DNA, were randomly divided into 5 groups(n = 7), including negative control(blank control, unrelated sequence control), positive control(lamivudine, anti-sense-LNA), and anti-gene-LNA experimental group. LNA was injected into transgenic mice by tail vein while lamivudine was administeredby gavage. Serum HBV DNA and HBs Ag levels were determined by fluorescence-based PCR and enzymelinked immune sorbent assay, respectively. HBV S gene expression amounts were assessed by reverse transcription polymerase chain reaction. Positive rates of HBsA g in liver cells were evaluated immunohistochemistry.RESULTS Average rate reductions of HBs Ag after treatment on the 3 rd, 5 th, and 7 th days were 32.34%, 45.96%, and 59.15%, respectively. The inhibitory effect of antigene-LNA on serum HBs Ag peaked on day 7, with statistically significant differences compared with pretreatment(0.96 ± 0.18 vs 2.35 ± 0.33, P < 0.05) and control values(P < 0.05 for all). Average reduction rates of HBV DNA on the 3 rd, 5 th, and 7 th days were 38.55%, 50.95%, and 62.26%, respectively. This inhibitory effect peaked on the 7 th day after treatment with anti-gene-LNA, with statistically significant differences compared with pre-treatment(4.17 ± 1.29 vs 11.05 ± 1.25, P < 0.05) and control values(P < 0.05 for all). The mR NA levels of the HBV S gene(P < 0.05 for all) and rates of HBsA g positive liver cells(P < 0.05 for all) were significantly reduced compared with the control groups. Liver and kidney function, and histology showed no abnormalities. CONCLUSION Anti-gene-LNA targeting the S gene of HBV displays strong inhibitory effects on HBV in transgenic mice, providing theoretical and experimental bases for gene therapy in HBV.
基金supported by the National Natural Science Foundation of China (Grant No. 41672295)
文摘Locked segments are recognized as a critical role that controls the stability of rock slopes but remain an unclear and challenging problem with respect to their role incorporated into the failure mechanism.In order to study the effect of the locked segments on the initial failure process of rockslides,thirty-six groups of locked segment specimens with three different lithologies were prepared,direct shear tests were carried out to obtain the accelerations caused by brittle failure of the locked segment specimens.Experiment results showed that the maximum accelerations caused by the brittle failure of locked segment specimens was 2.91 g in the horizontal direction,and 3.18 g in the vertical direction.We took the Wangjiayan rockslide in 2008 Wenchuan earthquake as an example,the critical balance condition of the sliding mass under combined effect of gravity and accelerations induced by brittle failure of locked segment was analyzed,which indicated that the initial failure process of the Wangjiayan rockslides was notably influenced by the existence of the locked segment.The departure acceleration and direction of the Wangjiayan rockslide were proposed.The study results can provide a new insight into the understanding of the initial failure mechanism of rockslides with locked segments.
基金National Key R&D Program of China (Nos. 2017YFE0301900 and 2017YFE0301100)National Natural Science Foundation of China (No. 11675083)+1 种基金the Fundamental Research Funds for the Central Universities (Nos. DUT18ZD101 and DUT17LK38)the Dalian Youth Science and Technology Project Support Program (No. 2015R01).
文摘The effects of externally applied resonant magnetic perturbation (RMP) on the locked mode of the neoclassical tearing mode (NTM) are numerically investigated by means of a set of reduced magnetohydrodynamic equations.It is found that,for a small bootstrap current fraction,three regimes,namely the slight suppression regime,the small locked island (SLI) regime and the big locked island (BLI) regime,are discovered with the increase of RMP strength.For a much higher bootstrap current fraction,however,a new oscillation regime appears instead of the SLI regime,although the other regimes still remain.The physical process in each regime is analyzed in detail based on the phase difference between the NTM and the RMP.Moreover,the critical values of the RMP in both SLI and BLI regimes are obtained,and their dependence on key plasma parameters is discussed as well.
基金supported by the National MCF Energy R&D Program of China(No.2018YFE0309100)National Natural Science Foundation of China(NSFC)(No.11905078)‘the Fundamental Research Funds for the Central Universities’(No.2020kfy XJJS003)。
文摘Magnetohydrodynamic(MHD)instabilities are widely observed during tokamak plasma operation.Magnetic diagnostics provide important information which supports the understanding and control of MHD instabilities.This paper presents the current status of the magnetic diagnostics dedicated to measuring MHD instabilities at the J-TEXT tokamak;the diagnostics consist of five Mirnov probe arrays for measuring high-frequency magnetic perturbations and two saddle-loop arrays for low-frequency magnetic perturbations,such as the locked mode.In recent years,several changes have been made to these arrays.The structure of the probes in the poloidal Mirnov arrays has been optimized to improve their mechanical strength,and the number of in-vessel saddle loops has also been improved to support better spatial resolution.Due to the installation of high-field-side(HFS)divertor targets in early 2019,some of the probes were removed,but an HFS Mirnov array was designed and installed behind the targets.Owing to its excellent toroidal symmetry,the HFS Mirnov array has,for the first time at J-TEXT,provided valuable new information about the locked mode and the quasi-static mode(QSM)in the HFS.Besides,various groups of magnetic diagnostics at different poloidal locations have been systematically used to measure the QSM,which confirmed the poloidal mode number m and the helical structure of the QSM.By including the HFS information,the 2/1 resonant magnetic perturbation(RMP)-induced locked mode was measured to have a poloidal mode number m of~2.
文摘Aim. Comparison of the trascranial Doppler (TCD) characteristics of cerebral circulation in persistent vegetative status (PVS), locked in syndrome and brain death patients. Methods. Using TCD ultrasound to detect the flow velocity and waveform patterns of middle cerebral artery (MCA) and basilar artery (BA) in patients with PVS, locked in syndrome and brain death. Results. The mean velocities of middle cerebral artery (Vmca) and basilar artery (Vba) were 30.0cm/s and 24.3cm/s in PVS patients respectively, which decreased 45.0% and 14.4% in comparing with normal value. For patients with locked in syndrome, Vmca and Vba were 49.7cm/s and 9.8cm/s, which decreased 5.0% and 61.7% than the normal value respectively. These results showed that the decrease of anterior circulation was predominant in PVS, and the decrease of posterior circulation was predominant in locked in syndrome. A unique diastolic reverse flow, short peak systolic wave or undetectable flow signal in middle cerebral artery were predominant in brain death patients, which was completely different from that of either PVS or locked in syndrome. Conclusion. TCD was a valuable tool in distinguishing PVS, locked in syndrome and brain death patients according to the differences in velocities and patterns of anterior and posterior cerebral arteries.
基金Project supported by the Natural Science Foundation of Jiangsu Province,China(Grant Nos.BK20130453 and BK20130434)the National Natural Science Foundation of China(Grant No.11304271)
文摘We report an efficient continuous-wave self-Raman laser at 1176 nm based on a 20-mm-long composite YVO4/Nd：YVO4/YVO4 crystal and pumped by a wavelength-locked 878.9 nm diode laser.A maximum output power of 5.3 W is achieved at a pump power of 26 W,corresponding to an optical conversion efficiency of 20%and a slope efficiency of 21%.The Raman threshold for the diode pump power was only 0.92 W.The results reveal that in-band pumping by a wavelength-locked diode laser significantly enhances output power and efficiency of self-Raman lasers by virtue of improved pump absorption and relieved thermal loading.
基金supported by the National Natural Science Foundation of China(Grant Nos.11773060,11973074,U1831137 and 11703070)National Key Basic Research and Development Program(2018YFA0404702)+1 种基金Shanghai Key Laboratory of Space Navigation and Positioning(3912DZ227330001)the Key Laboratory for Radio Astronomy of CAS。
文摘In deep space exploration,many engineering and scientific requirements require the accuracy of the measured Doppler frequency to be as high as possible.In our paper,we analyze the possible frequency measurement points of the third-order phase-locked loop(PLL)and find a new Doppler measurement strategy.Based on this finding,a Doppler frequency measurement algorithm with significantly higher measurement accuracy is obtained.In the actual data processing,compared with the existing engineering software,the accuracy of frequency of 1 second integration is about 5.5 times higher when using the new algorithm.The improved algorithm is simple and easy to implement.This improvement can be easily combined with other improvement methods of PLL,so that the performance of PLL can be further improved.
基金the collaborative research program from the Microwave Energy Transmission Laboratory(METLAB)Research Insti⁃tute for Sustainable Humanosphere(RISH)Kyoto University and National Institute of Information and Communications Technology(NICT),JAPAN under Grant No.02401.
文摘Applications using simultaneous wireless information and power transfer(SWIPT)have increased significantly.Wireless communication technologies can be combined with the Internet of Things to develop many innovative applications using SWIPT,which is mainly based on wireless energy harvesting from electromagnetic waves used in communications.Wireless power transfer that uses magnetrons has been developed for communication technologies.Injection-locked magnetrons that can be used to facilitate high-power SWIPT for several devices are reviewed in this paper.This new technology is expected to pave the way for promoting the application of SWIPT in a wide range of fields.
基金supported by the National Natural Science Foundation of China(No.61108021)the Fundamental Research Funds for the Central Universities(Nos.2013JBM091 and S16JB00010)
文摘In this paper, a self-mode-locked Nd:YVO_4 picosecond vortex laser is demonstrated, which can operate on the different Laguerre-Gaussian(LG) modes at 1 064 nm. A π/2 mode converter is utilized to realize the picosecond vortex laser with LG mode transformed from the high-order Hermite-Gaussian(HG) mode. For the proposed laser, the mode-locked pulse repetition rate is 1.81 GHz. The average output powers of LG_(12) mode and LG_(02) mode are 1.241 W and 1.27 W, respectively, and their slope efficiencies are 23.2% and 24%, respectively.
基金supported by the National Magnetic Confinement Fusion Science Program of China(Nos.2010GB107004,2011GB109001,2008CB717805)National Natural Science Foundation of China(Nos.11275080,10935004)
文摘Prediction of disruptions caused by locked modes using the Back-Propagation （BP） neural network is completed on J-TEXT tokamak. The network, which is based on the BP neural network, uses Mirnov coils and locked mode coils signals as input data, and outputs a signal including information of prediction of locked mode. The rate of successful prediction of locked modes is more than 90%. For intrinsic locked mode disruptions, the network can give a prewarning signal about 1 ms ahead of the locking-time. For the disruption caused by resonant magnetic perturbation （RMPs） locked modes, the network can give a prewarning signal about 10 ms ahead of the locking-time.
基金financially supported by the National Natural Science Foundation of China (Nos.21475091,21775106)
文摘Circulating tumor DNA(ctDNA),carrying tumor-specific sequence mutations,is a promising biomarker for classification,diagnosis and prognosis of cancers.However,there is still a great challenge in discriminating single-base difference between ctDNA and its coexisting analogue(normal circulating DNA,ncDNA)at a serum sample.A locked nucleic acid(LNA)probe combined with a-HL nanopore sensor was designed,which achieved a high signal-to-background ratio(SBR)of^8.34 × 10^3,as well as a significant discrimination capability(~12.3 times)of single-base diffe rence.The accurate discrimination strategy is label-free,convenient,selective and sensitive,which has great potential in the early diagnosis of diseases and biomedical research fields.
基金Supported by the National Research Foundation of Korea,No.2022R1A2B5B01001421the Korea Health Technology R&D Project through the Korea Health Industry Development Institute,the Ministry of Health&Welfare,Republic of Korea,No.HI22C0476.
文摘BACKGROUND The presence of two distinct hepatitis B virus(HBV)Pol RT polymorphisms,rt269L and rt269I,could contribute to the unique clinical or virological phenotype of HBV genotype C2.Therefore,a simple and sensitive method capable of identifying both types in chronic hepatitis B(CHB)patients infected with genotype C2 should be developed.AIM To develop a novel simple and sensitive locked nucleic acid(LNA)-real timepolymerase chain reaction(RT-PCR)method capable of identifying two rt269 types in CHB genotype C2 patients.METHODS We designed proper primer and probe sets for LNA-RT-PCR for the separation of rt269 types.Using synthesized DNAs of the wild type and variant forms,melting temperature analysis,detection sensitivity,and endpoint genotyping for LNA-RT-PCR were performed.The developed LNA-RT-PCR method was applied to a total of 94 CHB patients of genotype C2 for the identification of two rt269 polymorphisms,and these results were compared with those obtained by a direct sequencing protocol.RESULTS The LNA-RT-PCR method could identify two rt269L and rt269I polymorphisms of three genotypes,two rt269L types[‘L1’(WT)and‘L2’]and one rt269I type(‘I’)in single(63 samples,72.4%)or mixed forms(24 samples,27.6%)in 87(92.6%sensitivity)of 94 samples from Korean CHB patients.When the results were compared with those obtained by the direct sequencing protocol,the LNA-RT-PCR method showed the same results in all but one of 87 positive detected samples(98.9%specificity).CONCLUSION The newly developed LNA-RT-PCR method could identify two rt269 polymorphisms,rt269L and rt269I,in CHB patients with genotype C2 infections.This method could be effectively used for the understanding of disease progression in genotype C2 endemic areas.
基金the National Natural Science Foundation of China.
文摘Novel bicyclic isonucleosides, 2′-deoxy-2′ -nucleobase-5′-deoxy-1′ , 4′ : 3′ , 6′ -dianhydro- D-mannitol 10a-10c, were synthesized from D-glucose. The computer-assisted molecular simu- lation indicated that the sugar conformations of compounds 10a-10c were restricted to N-con- formation.
基金The project supported by National Natural Science Foundation of China under Grant No. 10405012
文摘Considering the density dependence of quark mass, we investigate the phase transition between the （unpaired） strange quark matter and the color-flavor-locked matter, which are supposed to be two candidates for the ground state of strongly interacting matter. We lind that if the current mass of strange quark m, is smmall, the strange quark matter remains stable unless the baryon density is very high. If m, is large, the phase transition from the strange quark matter to the color-flavor-locked matter in particular to its gapless phase is found to be different from the results predicted by previous works. A complicated phase diagram of three-flavor quark matter is presented, in which the color-flavor-locked phase region is suppressed for moderate densities.
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An injection-Locked divider(ILD)can provide good synchronization at lower inputsignal to noise ratio,which is its advantage over other types of divider.The general expressionof phase equation and equivalent model are presented for the ILD with an input additive noise.In the absence of noise the performance of the phase-modulated signal through the ILD andsynchronous ranges of the ILD are given.The effects of the additive noise on the ILD arediscuued.The injection-locked amplifier(ILA)is only a particular case in which n=1,thereforethe given results arc applicable to the ILA.
