BACKGROUND Percutaneous transhepatic biliary drainage(PTBD)is one of the primary clinical treatment options for patients with obstructive jaundice.In recent years,PTBD assisted by three-dimensional(3D)reconstruction t...BACKGROUND Percutaneous transhepatic biliary drainage(PTBD)is one of the primary clinical treatment options for patients with obstructive jaundice.In recent years,PTBD assisted by three-dimensional(3D)reconstruction technology has been widely implemented,but its advantages over traditional methods remains inconclusive.Thus,a discussion is warranted.AIM To explore the safety and efficacy of 3D reconstruction technology-assisted PTBD.METHODS We systematically searched the databases including the Cochrane Library,PubMed,EMBASE,Web of Science and China National Knowledge Infrastructure.The search period extended from the establishment of each database to November,2024.We screened the literature according to predefined inclusion and exclusion criteria,assessed the quality of the studies,and extracted data.Meta-analysis was performed using Revman 5.4.1 software.RESULTS A total of 15 studies were included,involving 1434 patients.The results of the meta-analysis showed that compared with the traditional group,the overall post-operative complications rate in the 3D reconstruction technology group was significantly lower[odds ratio=0.25;95%confidence interval(CI):0.17-0.36,P<0.00001].The overall puncture success rate in the 3D reconstruction group was better than those in the traditional group(odds ratio=3.61;95%CI:1.98-6.55,P<0.0001).However,there was no significant difference between the two groups in the reduction levels of postoperative total bilirubin(mean difference=-1.38;95%CI:-3.29 to 0.53,P=0.16).Subgroup analysis were conducted on the surgery time according to guidance stages of the 3D reconstruction,3D reconstruction imaging modalities,and types of studies.The results were stable,with no significant changes observed.CONCLUSION 3D reconstruction technology significantly improves the puncture success rate and safety of PTBD.However,it has no significant advantage in bile drainage effectiveness.Continued research is warranted to further explore its clinical value and optimize its application.展开更多
The traditional computed tomography(CT)reconstruction methods are noisy,low resolution,poor contrast,and generally not suitable to detect the smaller flaws.Besides,the filter design is also difficult.The CT characteri...The traditional computed tomography(CT)reconstruction methods are noisy,low resolution,poor contrast,and generally not suitable to detect the smaller flaws.Besides,the filter design is also difficult.The CT characteristics reconstruction technology was brought forward to improve in these aspects,which is defined to directly reconstruct the characteristics of the projection for the best requirements not the overall image quality.The two-dimension(2D)and three-dimension(3D)CT characteristics reconstruction algorithm were firstly introduced,then by detailed analysis,experimental results and comparsion of parameters calculated,its advantages in keeping better high-frequency feature,better noise immunity,short time-consuming and easier design are verified.展开更多
The fatigue performance of a workpiece depends on its surface quality.In traditional fatigue life prediction,the effect of surface quality is commonly accounted for by using empirical correction factors,which is impre...The fatigue performance of a workpiece depends on its surface quality.In traditional fatigue life prediction,the effect of surface quality is commonly accounted for by using empirical correction factors,which is imprecise when safety is of great concern.For surface quality,the surface topography is an important parameter,which introduces stress concentration that reduces the fatigue life.It is not feasible to test the stress concentration of different surface topographies.On the one hand,it is time-consuming and high-cost,and on the other hand,it cannot reflect the general statistical characteristics.With the help of surface reconstruction technology and interpolation method,a more efficient and economic approach is proposed,where FE simulation of workpiece with the reconstructed surface topography is used as a foundation for fatigue life prediction.The relationship between surface roughness(Sa)and fatigue life of the workpiece is studied with the proposed approach.展开更多
Objective To discuss the measurement of bone tumor volume on the basis of three dimensional images segmentation technology. Methods Twenty patients with lacunar bone tumor from Tianjin Hospital and Tongji Hospital wer...Objective To discuss the measurement of bone tumor volume on the basis of three dimensional images segmentation technology. Methods Twenty patients with lacunar bone tumor from Tianjin Hospital and Tongji Hospital were included in the展开更多
By studying the traditional spectral reflectance reconstruction method, spectral reflectance and the relative spectral power distribution of a lighting source are sparsely decomposed, and the orthogonal property of th...By studying the traditional spectral reflectance reconstruction method, spectral reflectance and the relative spectral power distribution of a lighting source are sparsely decomposed, and the orthogonal property of the principal component orthogonal basis is used to eliminate basis; then spectral reflectance data are obtained by solving a sparse coefficient. After theoretical analysis, the spectral reflectance reconstruction based on sparse prior knowledge of the principal component orthogonal basis by a single-pixel detector is carried out by software simulation and experiment. It can reduce the complexity and cost of the system, and has certain significance for the improvement of multispectral image acquisition technology.展开更多
In this paper,we proposed and experimentally demonstrated an 8-channel O-band distributed feedback(DFB)laser array with highly uniform 400 GHz spacing and high output power for optical input/output(I/O)technology.The ...In this paper,we proposed and experimentally demonstrated an 8-channel O-band distributed feedback(DFB)laser array with highly uniform 400 GHz spacing and high output power for optical input/output(I/O)technology.The grating phase is precisely controlled,and an equivalentπphase shift is implemented in the laser cavity via the reconstruction equivalent chirp(REC)technology.Anti-reflection(AR)and high-reflection(HR)films are coated on the front and rear facets,respectively,to enhance output power.The equivalentπphase shift is strategically placed near the HR film facet to improve the yield of the single longitudinal mode.Operating with a 400 GHz wavelength spacing,the proposed DFB laser array meets the continuous wave-wavelength division multiplexing multi-source agreement(CW-WDM MSA)specifications.The proposed DFB laser array is flip-chip bonded to a thin-film circuit with an aluminum nitride(AlN)submount to reduce the thermal resistance and enhance the output power.Compared to the p-side-up structure,the flip-chip bonding design significantly reduces junction temperature by 28%and increases maximum output power by approximately 20%.This design effectively lowers the thermal resistance of the chip and enhances its heat dissipation properties.At a bias current of 110 mA,the laser demonstrates wavelength deviations below 1.579 GHz and side-mode suppression ratios above 50 dB.The far-field divergence is measured at 25.8°×30.1°,and the Lorentzian linewidth is 3.28 MHz.Increasing the bias current to250 mA results in a laser output power exceeding 80 mW.Furthermore,the relative intensity noise(RIN)for all 8 channels is below-135.3 d B/Hz.The proposed flip-chip bonded 8-channel high-power DFB laser array demonstrates uniform wavelength spacing,high output power,and stable single longitudinal mode performance,making it a promising candidate for multiple wavelength laser sources in optical I/O technology.展开更多
In this paper, time series with stable convergence, saddles, Hopf bifurcations and chaotic points in one kind of complicated systems have been studied in respects of： fractal characteristic and fractal dimension. By ...In this paper, time series with stable convergence, saddles, Hopf bifurcations and chaotic points in one kind of complicated systems have been studied in respects of： fractal characteristic and fractal dimension. By using phase space reconstruction technology of chaotic time series, work of reconstruction has been done respectively on these four different conditions and further by applying wavelet network models, work of modeling and prediction have been done accordingly. The results indicate： treatment of zero mean value in the identification of the chaotic models has no obvious influence on precision and length of predictions, while the treatment by Fourier Filter can damage effectiveness of prediction.展开更多
基金Supported by the Natural Science Foundation of Fujian Province,No.2022J011442.
文摘BACKGROUND Percutaneous transhepatic biliary drainage(PTBD)is one of the primary clinical treatment options for patients with obstructive jaundice.In recent years,PTBD assisted by three-dimensional(3D)reconstruction technology has been widely implemented,but its advantages over traditional methods remains inconclusive.Thus,a discussion is warranted.AIM To explore the safety and efficacy of 3D reconstruction technology-assisted PTBD.METHODS We systematically searched the databases including the Cochrane Library,PubMed,EMBASE,Web of Science and China National Knowledge Infrastructure.The search period extended from the establishment of each database to November,2024.We screened the literature according to predefined inclusion and exclusion criteria,assessed the quality of the studies,and extracted data.Meta-analysis was performed using Revman 5.4.1 software.RESULTS A total of 15 studies were included,involving 1434 patients.The results of the meta-analysis showed that compared with the traditional group,the overall post-operative complications rate in the 3D reconstruction technology group was significantly lower[odds ratio=0.25;95%confidence interval(CI):0.17-0.36,P<0.00001].The overall puncture success rate in the 3D reconstruction group was better than those in the traditional group(odds ratio=3.61;95%CI:1.98-6.55,P<0.0001).However,there was no significant difference between the two groups in the reduction levels of postoperative total bilirubin(mean difference=-1.38;95%CI:-3.29 to 0.53,P=0.16).Subgroup analysis were conducted on the surgery time according to guidance stages of the 3D reconstruction,3D reconstruction imaging modalities,and types of studies.The results were stable,with no significant changes observed.CONCLUSION 3D reconstruction technology significantly improves the puncture success rate and safety of PTBD.However,it has no significant advantage in bile drainage effectiveness.Continued research is warranted to further explore its clinical value and optimize its application.
基金National Natural Science Foundation of China(No.61471325)
文摘The traditional computed tomography(CT)reconstruction methods are noisy,low resolution,poor contrast,and generally not suitable to detect the smaller flaws.Besides,the filter design is also difficult.The CT characteristics reconstruction technology was brought forward to improve in these aspects,which is defined to directly reconstruct the characteristics of the projection for the best requirements not the overall image quality.The two-dimension(2D)and three-dimension(3D)CT characteristics reconstruction algorithm were firstly introduced,then by detailed analysis,experimental results and comparsion of parameters calculated,its advantages in keeping better high-frequency feature,better noise immunity,short time-consuming and easier design are verified.
基金Projects(51535012,U1604255)supported by the National Natural Science Foundation of ChinaProject(2016JC2001)supported by the Key Research and Development Project of Hunan Province,China
文摘The fatigue performance of a workpiece depends on its surface quality.In traditional fatigue life prediction,the effect of surface quality is commonly accounted for by using empirical correction factors,which is imprecise when safety is of great concern.For surface quality,the surface topography is an important parameter,which introduces stress concentration that reduces the fatigue life.It is not feasible to test the stress concentration of different surface topographies.On the one hand,it is time-consuming and high-cost,and on the other hand,it cannot reflect the general statistical characteristics.With the help of surface reconstruction technology and interpolation method,a more efficient and economic approach is proposed,where FE simulation of workpiece with the reconstructed surface topography is used as a foundation for fatigue life prediction.The relationship between surface roughness(Sa)and fatigue life of the workpiece is studied with the proposed approach.
文摘Objective To discuss the measurement of bone tumor volume on the basis of three dimensional images segmentation technology. Methods Twenty patients with lacunar bone tumor from Tianjin Hospital and Tongji Hospital were included in the
基金supported by the National Natural Science Foundation of China (Grant No.61405115)the Natural Science Foundation of Shanghai (Grant No.14ZR1428400)+1 种基金the Innovation Project of Shanghai Municipal Education Commission (Grant No.14YZ099)National Basic Research Program of China (973 Program) (Grant No.2015CB352004)
文摘By studying the traditional spectral reflectance reconstruction method, spectral reflectance and the relative spectral power distribution of a lighting source are sparsely decomposed, and the orthogonal property of the principal component orthogonal basis is used to eliminate basis; then spectral reflectance data are obtained by solving a sparse coefficient. After theoretical analysis, the spectral reflectance reconstruction based on sparse prior knowledge of the principal component orthogonal basis by a single-pixel detector is carried out by software simulation and experiment. It can reduce the complexity and cost of the system, and has certain significance for the improvement of multispectral image acquisition technology.
基金supported by the National Natural Science Foundation of China(No.62404098)the Natural Science Foundation of Jiangsu Province of China(No.BK20241196)the National Key Research and Development Program of China(Nos.2023YFB2806400,2021YFB2801902,and 2018YFB2201801)。
文摘In this paper,we proposed and experimentally demonstrated an 8-channel O-band distributed feedback(DFB)laser array with highly uniform 400 GHz spacing and high output power for optical input/output(I/O)technology.The grating phase is precisely controlled,and an equivalentπphase shift is implemented in the laser cavity via the reconstruction equivalent chirp(REC)technology.Anti-reflection(AR)and high-reflection(HR)films are coated on the front and rear facets,respectively,to enhance output power.The equivalentπphase shift is strategically placed near the HR film facet to improve the yield of the single longitudinal mode.Operating with a 400 GHz wavelength spacing,the proposed DFB laser array meets the continuous wave-wavelength division multiplexing multi-source agreement(CW-WDM MSA)specifications.The proposed DFB laser array is flip-chip bonded to a thin-film circuit with an aluminum nitride(AlN)submount to reduce the thermal resistance and enhance the output power.Compared to the p-side-up structure,the flip-chip bonding design significantly reduces junction temperature by 28%and increases maximum output power by approximately 20%.This design effectively lowers the thermal resistance of the chip and enhances its heat dissipation properties.At a bias current of 110 mA,the laser demonstrates wavelength deviations below 1.579 GHz and side-mode suppression ratios above 50 dB.The far-field divergence is measured at 25.8°×30.1°,and the Lorentzian linewidth is 3.28 MHz.Increasing the bias current to250 mA results in a laser output power exceeding 80 mW.Furthermore,the relative intensity noise(RIN)for all 8 channels is below-135.3 d B/Hz.The proposed flip-chip bonded 8-channel high-power DFB laser array demonstrates uniform wavelength spacing,high output power,and stable single longitudinal mode performance,making it a promising candidate for multiple wavelength laser sources in optical I/O technology.
基金This project is supported by National Natural Science Foundation of China （70271071）, Education department of Tianjin （20041702）
文摘In this paper, time series with stable convergence, saddles, Hopf bifurcations and chaotic points in one kind of complicated systems have been studied in respects of： fractal characteristic and fractal dimension. By using phase space reconstruction technology of chaotic time series, work of reconstruction has been done respectively on these four different conditions and further by applying wavelet network models, work of modeling and prediction have been done accordingly. The results indicate： treatment of zero mean value in the identification of the chaotic models has no obvious influence on precision and length of predictions, while the treatment by Fourier Filter can damage effectiveness of prediction.
