BACKGROUND Pachymic acid(PA)is derived from Poria cocos.PA has a variety of pharmacological and inhibitory effects on various tumors.However,the mechanism of action of PA in gastric cancer(GC)remains unclear.AIM To in...BACKGROUND Pachymic acid(PA)is derived from Poria cocos.PA has a variety of pharmacological and inhibitory effects on various tumors.However,the mechanism of action of PA in gastric cancer(GC)remains unclear.AIM To investigate the mechanism of PA in treating GC via the combination of network pharmacology and experimental verification.METHODS The GeneCards and OMIM databases were used to derive the GC targets,while the Pharm Mapper database provided the PA targets.Utilizing the STRING database,a protein-protein interaction network was constructed and core targets were screened.The analyses of Gene Ontology,Kyoto Encyclopedia of Genes and Genomes(KEGG),and gene set enrichment analysis were conducted,and molecular docking and clinical correlation analyses were performed on the core targets.Ultimately,the network pharmacology findings were validated through in vitro cell assays,encompassing assessments of cell viability,apoptosis,cell cycle,cloning,and western blot analysis.RESULTS According to network pharmacology analysis,the core targets were screened,and the PI3K/AKT signaling pathway is likely to be the mechanism by which PA effectively treats GC,according to KEGG enrichment analysis.The experimental findings showed that PA could control PI3K/AKT signaling to prevent GC cell proliferation,induce apoptosis,and pause the cell cycle.CONCLUSION Network pharmacology demonstrated that PA could treat GC by controlling a variety of signaling pathways and acting on a variety of targets.This has also been supported by in vitro cell studies,which serve as benchmarks for further research.展开更多
Ship motion,with six degrees of freedom,is a complex stochastic process.Sea wind and waves are the primary influencing factors.Prediction of ship motion is significant for ship navigation.To eliminate errors,a path pr...Ship motion,with six degrees of freedom,is a complex stochastic process.Sea wind and waves are the primary influencing factors.Prediction of ship motion is significant for ship navigation.To eliminate errors,a path prediction model incorporating ship pitching was developed using the Gray topological method,after analyzing ship pitching motions.With the help of simple introduction to Gray system theory,we selected a group of threshold values.Based on an analysis of ship pitch angle sequences over 40 second intervals,a Grey metabolism GM(1,1) model was established according to the time-series which every threshold corresponded to.Forecasting future ship motion with the GM(1,1) model allowed drawing of the forecast curve with effective forecasting points.The precision of the test results show that the model is accurate,and the forecast results are reliable.展开更多
Femtosecond time-resolved coherent anti-Stokes Raman scattering (CARS) spectroscopy is used to investigate gaseous molecular dynamics. Due to the spectrally broad laser pulses, usually poorly resolved spectra result...Femtosecond time-resolved coherent anti-Stokes Raman scattering (CARS) spectroscopy is used to investigate gaseous molecular dynamics. Due to the spectrally broad laser pulses, usually poorly resolved spectra result from this broad spectroscopy. However, it can be demonstrated that by the electronic resonance enhancement optimization control a selective excitation of specific vibrational mode is possible. Using an electronically resonance-enhanced effect, iodine molecule specific CARS spectroscopy can be obtained from a mixture of iodine-air at room temperature and a pressure of 1 atm (corresponding to a saturation iodine vapour as low as about 35 Pa). The dynamics on either the electronically excited state or the ground state of iodine molecules obtained is consistent with previous studies (vacuum, heated and pure iodine) in the femtoseeond time resolved CARS spectroscopy, showing that an effective method of suppressing the non-resonant CARS background and other interferences is demonstrated.展开更多
We performed femtosecond time-resolved coherent anti-Stokes Raman scattering (fs-CARS) measurements on liquid toluene and PVK film. For both samples, we selectively excited the CH stretching vibrational modes and ob...We performed femtosecond time-resolved coherent anti-Stokes Raman scattering (fs-CARS) measurements on liquid toluene and PVK film. For both samples, we selectively excited the CH stretching vibrational modes and observed the expected quantum beat signals. The frequency of the well-defined beats is in good agreement with the energy difference between the two simultaneously excited modes, which demonstrates that a coherent coupling between the vibrational modes of the C H chemical bonds exists at the different positions of the molecules. The dephasing times of the excited modes are obtained simultaneously.展开更多
In order to effectively predict occurrence quantity of Myzus persicae, BP neural network theory and method was used to establish prediction model for oc- currence quantity of M. persicae. Meanwhile, QPSO algorithm was...In order to effectively predict occurrence quantity of Myzus persicae, BP neural network theory and method was used to establish prediction model for oc- currence quantity of M. persicae. Meanwhile, QPSO algorithm was used to optimize connection weight and threshold value of BP neural network, so as to determine. the optimal connection weight and threshold value. The historical data of M. persica quantity in Hongta County, Yuxi City of Yunnan Province from 2003 to 2006 was adopted as training samples, and the occurrence quantities of M. persicae from 2007 to 2009 were predicted. The prediction accuracy was 99.35%, the mini- mum completion time was 30 s, the average completion time was 34.5 s, and the running times were 19. The prediction effect of the model was obviously superior to other prediction models. The experiment showed that this model was more effective and feasible, with faster convergence rate and stronger stability, and could solve the similar problems in prediction and clustering. The study provides a theoretical basis for comprehensive prevention and control against M. persicae.展开更多
We report on the theoretical and the experimental investigations of the coherent phonon dynamics in sapphire crystal using the femtosecond time-resolved coherent anti-Stokes Raman scattering (fs-CARS) technique. The...We report on the theoretical and the experimental investigations of the coherent phonon dynamics in sapphire crystal using the femtosecond time-resolved coherent anti-Stokes Raman scattering (fs-CARS) technique. The temporal chirped white-light continuum (WLC) is used for the Stokes pulse, therefore we can perform the selective excitation of the phonon modes without using a complicated laser system. The expected quantum beat phenomenon is clearly observed. The theoretical formulas consist very well with the experimental results. The dephasing times of the excited phonon modes, the wavenumber difference, and the phase shift between the simultaneously excited modes are obtained and discussed. This work opens up a way to study directly high-frequency coherent phonon dynamics in bulk crystals on a femtosecond time scale and is especially helpful for understanding the nature of coherent phonons.展开更多
The traceability management system for pigs based on personal digital assistant (PDA) was constructed by software engineering method to provide the traceability management for pork safety. This traceability system i...The traceability management system for pigs based on personal digital assistant (PDA) was constructed by software engineering method to provide the traceability management for pork safety. This traceability system included information managements for pig breeding and pig quaran- tine inspection supervision. It also realized the record and supervision of pig information, feed usage, veterinary drug usage and quarantine inspec- tion. We mainly introduced the designs of systemic structure and functional structure of the traceability system and key techniques of system imple- mentation.展开更多
A recently developed time-resolved coherent anti-Stokes Raman scattering(tr-CARS) technique allows the measurement of vibrational coherences with high frequency differences with the ambient environment.The method is b...A recently developed time-resolved coherent anti-Stokes Raman scattering(tr-CARS) technique allows the measurement of vibrational coherences with high frequency differences with the ambient environment.The method is based on the short spatial extension of femtosecond pulses with a broadband tunable nonlinear optical parametric amplifier(NOPA) and an internal time delay between the probe and pump/Stokes pulse pair in the CARS process.The different beat frequencies between Raman modes can be selectively detected as oscillations in the tr-CARS transient signal with the broadband tunable NOPA.In this work,we aim at the Raman C-H stretching vibrations from 2800 cm 1 to 3000 cm 1,within which the different vibrational modes in both ethanol and methanol are selectively excited and simultaneously detected.The high time resolution of the experimental set-up allows one to monitor the vibrational coherence dynamics and to observe the quantum beat phenomena on a terahertz scale.This investigation indicates that the femtosecond tr-CARS technique is a powerful tool for the real-time monitoring and detection of molecular and biological agents,including airborne contaminants such as bacterial spores,viruses and their toxins.展开更多
A variant of all-resonant CARS named electronic-resonant enhancement CARS (ERE-CARS) is applied to measure the methanol-water solution concentration at room temperature. The measurements are performed using the ERE-...A variant of all-resonant CARS named electronic-resonant enhancement CARS (ERE-CARS) is applied to measure the methanol-water solution concentration at room temperature. The measurements are performed using the ERE-CARS signal of the Raman vibrations near the C--H stretching modes (at 2835 and 2942 cm^-1) in methanol. By changing the timing (△t〉0) of the laser pulses of this non-degenerate four wave mixing technique, the concentration information based on the vibrational dynamics of the C--H bonds can be successfully detected as the frequency-spread dephasing rate duiing the first few hundred fs in the ERE-CARS signal with high sensitivity and accuracy. Femtosecond time-resolved ERE-CARS technique is applied to the concentration analysis of a mixture of the organic solution. This investigation indicates that femtosecond time-resolved ERE-CARS technique might be a powerful tool for real-time detection for solution concentration of different liquids.展开更多
Streak tube imaging lidar (STIL) is an active imaging system that has a high range accuracy with tile use of a pulsed lapser transmitter and streak tube receiver to produce 3D range inlages. This work investigates t...Streak tube imaging lidar (STIL) is an active imaging system that has a high range accuracy with tile use of a pulsed lapser transmitter and streak tube receiver to produce 3D range inlages. This work investigates the effect of tile time bin size oil the range accuracy of STIL systems based on the peak detection algorithm. The nunlerical simulation indicates that the time bin size has a significant effect on the range aceuracy, resulting in a modified analytical estimate of the range error. An indoor experilnent with a planar target is carried out to validate the theory that shows the linear relationship between tile range error and the time bin size. Finer 3D depth iinages of a fist model are acquired by using a smaller time bin size and the best range error of 0.003 In is achieved with the optimal time bin size of 0.07 ns.展开更多
In this paper, we focus on studying approximate solutions of damped oscillatory solutions of the compound KdV-Burgers equation and their error estimates. We employ the theory of planar dynamical systems to study trave...In this paper, we focus on studying approximate solutions of damped oscillatory solutions of the compound KdV-Burgers equation and their error estimates. We employ the theory of planar dynamical systems to study traveling wave solutions of the compound KdV-Burgers equation. We obtain some global phase portraits under different parameter conditions as well as the existence of bounded traveling wave solutions. Furthermore, we investigate the relations between the behavior of bounded traveling wave solutions and the dissipation coefficient r of the equation. We obtain two critical values of r, and find that a bounded traveling wave appears as a kink profile solitary wave if │r│ is greater than or equal to some critical value, while it appears as a damped oscillatory wave if │r│is less than some critical value. By means of analysis and the undetermined coefficients method, we find that the compound KdV-Burgers equation only has three kinds of bell profile solitary wave solutions without dissipation. Based on the above discussions and according to the evolution relations of orbits in the global phase portraits, we obtain all approximate damped oscillatory solutions by using the undetermined coefficients method. Finally, using the homogenization principle, we establish the integral equations reflecting the relations between exact solutions and approximate solutions of damped oscillatory solutions. Moreover, we also give the error estimates for these approximate solutions.展开更多
Formulation in terms of hypersingular integral equations for the interaction between straight and curved cracks in plane elasticity is obtained using the complex variable functions method. The curved length coordinate...Formulation in terms of hypersingular integral equations for the interaction between straight and curved cracks in plane elasticity is obtained using the complex variable functions method. The curved length coordinate method and a suitable numerical scheme are used to solve such integrals numerically for the unknown function, which are later used to find the stress intensity factor, SIF.展开更多
基金Supported by Ningxia Science and Technology Benefiting People Program,No.2022CMG03064National Natural Science Foundation of China,No.82260879Ningxia Natural Science Foundation,No.2022AAC03144 and 2022AAC02039.
文摘BACKGROUND Pachymic acid(PA)is derived from Poria cocos.PA has a variety of pharmacological and inhibitory effects on various tumors.However,the mechanism of action of PA in gastric cancer(GC)remains unclear.AIM To investigate the mechanism of PA in treating GC via the combination of network pharmacology and experimental verification.METHODS The GeneCards and OMIM databases were used to derive the GC targets,while the Pharm Mapper database provided the PA targets.Utilizing the STRING database,a protein-protein interaction network was constructed and core targets were screened.The analyses of Gene Ontology,Kyoto Encyclopedia of Genes and Genomes(KEGG),and gene set enrichment analysis were conducted,and molecular docking and clinical correlation analyses were performed on the core targets.Ultimately,the network pharmacology findings were validated through in vitro cell assays,encompassing assessments of cell viability,apoptosis,cell cycle,cloning,and western blot analysis.RESULTS According to network pharmacology analysis,the core targets were screened,and the PI3K/AKT signaling pathway is likely to be the mechanism by which PA effectively treats GC,according to KEGG enrichment analysis.The experimental findings showed that PA could control PI3K/AKT signaling to prevent GC cell proliferation,induce apoptosis,and pause the cell cycle.CONCLUSION Network pharmacology demonstrated that PA could treat GC by controlling a variety of signaling pathways and acting on a variety of targets.This has also been supported by in vitro cell studies,which serve as benchmarks for further research.
文摘Ship motion,with six degrees of freedom,is a complex stochastic process.Sea wind and waves are the primary influencing factors.Prediction of ship motion is significant for ship navigation.To eliminate errors,a path prediction model incorporating ship pitching was developed using the Gray topological method,after analyzing ship pitching motions.With the help of simple introduction to Gray system theory,we selected a group of threshold values.Based on an analysis of ship pitch angle sequences over 40 second intervals,a Grey metabolism GM(1,1) model was established according to the time-series which every threshold corresponded to.Forecasting future ship motion with the GM(1,1) model allowed drawing of the forecast curve with effective forecasting points.The precision of the test results show that the model is accurate,and the forecast results are reliable.
基金supported by the National Natural Science Foundation of China (Grant Nos.60878018 and 61008023)the Natural Scientific Research Innovation Foundation in Harbin Institute of Technology,China (Grant No.HIT.NSRIF.2009009)the Science and Technology Innovation Foundation,Harbin,China (Grant No.RC2007QN017030)
文摘Femtosecond time-resolved coherent anti-Stokes Raman scattering (CARS) spectroscopy is used to investigate gaseous molecular dynamics. Due to the spectrally broad laser pulses, usually poorly resolved spectra result from this broad spectroscopy. However, it can be demonstrated that by the electronic resonance enhancement optimization control a selective excitation of specific vibrational mode is possible. Using an electronically resonance-enhanced effect, iodine molecule specific CARS spectroscopy can be obtained from a mixture of iodine-air at room temperature and a pressure of 1 atm (corresponding to a saturation iodine vapour as low as about 35 Pa). The dynamics on either the electronically excited state or the ground state of iodine molecules obtained is consistent with previous studies (vacuum, heated and pure iodine) in the femtoseeond time resolved CARS spectroscopy, showing that an effective method of suppressing the non-resonant CARS background and other interferences is demonstrated.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 20573028 and 20973050)
文摘We performed femtosecond time-resolved coherent anti-Stokes Raman scattering (fs-CARS) measurements on liquid toluene and PVK film. For both samples, we selectively excited the CH stretching vibrational modes and observed the expected quantum beat signals. The frequency of the well-defined beats is in good agreement with the energy difference between the two simultaneously excited modes, which demonstrates that a coherent coupling between the vibrational modes of the C H chemical bonds exists at the different positions of the molecules. The dephasing times of the excited modes are obtained simultaneously.
基金Supported by Science and Technology Project of China National Tobacco Corporation(2009YN005&2010YN18&2010YN19)
文摘In order to effectively predict occurrence quantity of Myzus persicae, BP neural network theory and method was used to establish prediction model for oc- currence quantity of M. persicae. Meanwhile, QPSO algorithm was used to optimize connection weight and threshold value of BP neural network, so as to determine. the optimal connection weight and threshold value. The historical data of M. persica quantity in Hongta County, Yuxi City of Yunnan Province from 2003 to 2006 was adopted as training samples, and the occurrence quantities of M. persicae from 2007 to 2009 were predicted. The prediction accuracy was 99.35%, the mini- mum completion time was 30 s, the average completion time was 34.5 s, and the running times were 19. The prediction effect of the model was obviously superior to other prediction models. The experiment showed that this model was more effective and feasible, with faster convergence rate and stronger stability, and could solve the similar problems in prediction and clustering. The study provides a theoretical basis for comprehensive prevention and control against M. persicae.
基金supported by the National Natural Science Foundation of China (Grant No. 20973050)
文摘We report on the theoretical and the experimental investigations of the coherent phonon dynamics in sapphire crystal using the femtosecond time-resolved coherent anti-Stokes Raman scattering (fs-CARS) technique. The temporal chirped white-light continuum (WLC) is used for the Stokes pulse, therefore we can perform the selective excitation of the phonon modes without using a complicated laser system. The expected quantum beat phenomenon is clearly observed. The theoretical formulas consist very well with the experimental results. The dephasing times of the excited phonon modes, the wavenumber difference, and the phase shift between the simultaneously excited modes are obtained and discussed. This work opens up a way to study directly high-frequency coherent phonon dynamics in bulk crystals on a femtosecond time scale and is especially helpful for understanding the nature of coherent phonons.
基金supported by the Agricultural Science and Technology Innovation Project of Yunnan Province(2008LA020)sub-topic of National Key Technology R&D Program(2006BAD14B04)
文摘The traceability management system for pigs based on personal digital assistant (PDA) was constructed by software engineering method to provide the traceability management for pork safety. This traceability system included information managements for pig breeding and pig quaran- tine inspection supervision. It also realized the record and supervision of pig information, feed usage, veterinary drug usage and quarantine inspec- tion. We mainly introduced the designs of systemic structure and functional structure of the traceability system and key techniques of system imple- mentation.
基金supported by the National Natural Science Foundation of China (Grant Nos. 60878018 and 61008023)the Program of Excellentat Harbin Institute of Technology
文摘A recently developed time-resolved coherent anti-Stokes Raman scattering(tr-CARS) technique allows the measurement of vibrational coherences with high frequency differences with the ambient environment.The method is based on the short spatial extension of femtosecond pulses with a broadband tunable nonlinear optical parametric amplifier(NOPA) and an internal time delay between the probe and pump/Stokes pulse pair in the CARS process.The different beat frequencies between Raman modes can be selectively detected as oscillations in the tr-CARS transient signal with the broadband tunable NOPA.In this work,we aim at the Raman C-H stretching vibrations from 2800 cm 1 to 3000 cm 1,within which the different vibrational modes in both ethanol and methanol are selectively excited and simultaneously detected.The high time resolution of the experimental set-up allows one to monitor the vibrational coherence dynamics and to observe the quantum beat phenomena on a terahertz scale.This investigation indicates that the femtosecond tr-CARS technique is a powerful tool for the real-time monitoring and detection of molecular and biological agents,including airborne contaminants such as bacterial spores,viruses and their toxins.
基金supported by the National Natural Science Foundation of China (Grant No. 61008023)the Program of Excellent at Harbin Institute of Technology
文摘A variant of all-resonant CARS named electronic-resonant enhancement CARS (ERE-CARS) is applied to measure the methanol-water solution concentration at room temperature. The measurements are performed using the ERE-CARS signal of the Raman vibrations near the C--H stretching modes (at 2835 and 2942 cm^-1) in methanol. By changing the timing (△t〉0) of the laser pulses of this non-degenerate four wave mixing technique, the concentration information based on the vibrational dynamics of the C--H bonds can be successfully detected as the frequency-spread dephasing rate duiing the first few hundred fs in the ERE-CARS signal with high sensitivity and accuracy. Femtosecond time-resolved ERE-CARS technique is applied to the concentration analysis of a mixture of the organic solution. This investigation indicates that femtosecond time-resolved ERE-CARS technique might be a powerful tool for real-time detection for solution concentration of different liquids.
基金supported by the National Key Scientific Instrument and Equipment Development Projects of China under Grant No.2012YQ040164
文摘Streak tube imaging lidar (STIL) is an active imaging system that has a high range accuracy with tile use of a pulsed lapser transmitter and streak tube receiver to produce 3D range inlages. This work investigates the effect of tile time bin size oil the range accuracy of STIL systems based on the peak detection algorithm. The nunlerical simulation indicates that the time bin size has a significant effect on the range aceuracy, resulting in a modified analytical estimate of the range error. An indoor experilnent with a planar target is carried out to validate the theory that shows the linear relationship between tile range error and the time bin size. Finer 3D depth iinages of a fist model are acquired by using a smaller time bin size and the best range error of 0.003 In is achieved with the optimal time bin size of 0.07 ns.
基金Supported by the National Natural Science Foundation of China (No. 11071164)Shanghai Natural Science Foundation Project (No. 10ZR1420800)Leading Academic Discipline Project of Shanghai Municipal Government (No. S30501)
文摘In this paper, we focus on studying approximate solutions of damped oscillatory solutions of the compound KdV-Burgers equation and their error estimates. We employ the theory of planar dynamical systems to study traveling wave solutions of the compound KdV-Burgers equation. We obtain some global phase portraits under different parameter conditions as well as the existence of bounded traveling wave solutions. Furthermore, we investigate the relations between the behavior of bounded traveling wave solutions and the dissipation coefficient r of the equation. We obtain two critical values of r, and find that a bounded traveling wave appears as a kink profile solitary wave if │r│ is greater than or equal to some critical value, while it appears as a damped oscillatory wave if │r│is less than some critical value. By means of analysis and the undetermined coefficients method, we find that the compound KdV-Burgers equation only has three kinds of bell profile solitary wave solutions without dissipation. Based on the above discussions and according to the evolution relations of orbits in the global phase portraits, we obtain all approximate damped oscillatory solutions by using the undetermined coefficients method. Finally, using the homogenization principle, we establish the integral equations reflecting the relations between exact solutions and approximate solutions of damped oscillatory solutions. Moreover, we also give the error estimates for these approximate solutions.
基金Ministry of Science,Technology and Innovation(MOSTI),Malaysia for the Science Fund,Vot No.5450657
文摘Formulation in terms of hypersingular integral equations for the interaction between straight and curved cracks in plane elasticity is obtained using the complex variable functions method. The curved length coordinate method and a suitable numerical scheme are used to solve such integrals numerically for the unknown function, which are later used to find the stress intensity factor, SIF.