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Hybrid procedures for thoracoabdominal aortic aneurysms and dissections

Chinese Medical Journal 2013年第4期126卷 620-625页

作者： zhang hong-peng GUO Wei LIU Xiao-ping JIA Xin XIONG Jiang MA Xiao-hui Department of Vascular Surgery Chinese People's Liberation Army General Hospital Beijing 100853 China

Background Hybrid procedures including debranching of visceral and renal arteries followed by endovascular exclusion of the thoracoabdominal aortic aneurysm （TAAA） have recently been proposed as a less invasive alternative to conventional TAAA surgery. This study aimed to evaluate the immediate and long-term outcomes of hybrid procedures for TAAA in high-risk patients. Methods Between September 1998 and May 2012, 32 high-risk TAAA patients （five females, median age 61.5 years） underwent hybrid procedures at a single institution. Simultaneous approach and staged approach were performed on the basis of patients＇ conditions. Follow-up computed tomography angiography （CTA） was routinely performed before discharge and at 6, 12 months and annually thereafter. Results Procedural success was achieved in all cases. The median hospital stay was （21.5＋2.3） days, and the median procedure time was （420＋31） minutes. Blood loss averaged （2100_＋261） ml. A total of 124 visceral artery bypasses was performed. Two patients （6.3%） died within 30 days. One patient exhibited complete paraplegia （3.1%）. The visceral graft patency was 96.1% at 3 years. All-cause survival rates were 93.8%, 87.5%, 81.3% and 53.1% at 1, 2, 3 and 5 years, respectively. No patient died due to aortic events. The freedom rates from aortic events were 96.9%, 93.6%, 87.5%, 68.8% at 1,2, 3 and 5 years, respectively. Conclusions The results of visceral hybrid repair for high-risk patients with complex TAAAs are encouraging. However, the procedure is still a significant physiological insult to patients. Until branched and fenestrated endovascular repair become more common, hybrid procedure will continue to have a role in high-risk patients.

关键词： hybrid procedure thoraeoabdominal aortic aneurysm endovascular aortic repair," dissection," stent-grafi

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Fenestrated endovascular aortic repair for juxtarenal abdominal aortic aneurysm

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Chinese Medical Journal 2013年第3期126卷 409-414页

作者： GUO Wei zhang hong-peng LIU Xiao-ping JIA Xin XIONG Jiang MA Xiao-hui Department of Vascular Surgery Chinese People's Liberation Army General Hospital Beijing 100853 China

Background Endovascular stent-graft with fenestration can improve proximal sealing in patients with juxtarenal abdominal aortic aneurysm （JAAA）. The purpose of this study was to describe our primary experience and evaluate the safety and efficacy of fenestrated device for JAAA in high-risk patients. Methods Between March 2011 and May 2012, nine male patients （mean age, （79.6±8.6） years） with asymptomatic JAAAs underwent elective deployment of the Zenith fenestrated stent-grafts at a single institution. All patients were treated in the hybrid operating room under general anesthesia. Follow-up computed tomography angiography （CTA） was routinely performed before discharge, at 3, 6, and 12 months and annually thereafter. Results Procedural success was achieved in all cases. Total sixteen small fenestrations, two large fenestrations and eight scallops were used. Intra-operative complications occurred in four patients, which included one proximal type I endoleak, two type II endoleaks, and one renal artery dissection. The mean hospital stay was （8.9±1.4） days, mean blood loss was （360.5±46.8） ml, and mean iodinated contrast volume was （230.6±58.3） ml. The mean follow-up time was （7.6±4.2） months. The visceral graft patency was 100% until now. One patient had an increase of serum creatinine of more than 30%, but did not require dialysis. No patients died, no stent fractured, and migration were diagnosed during the follow-up. Conclusions The early results of fenestrated device for high-risk patients with complex JAAAs are satisfactory. However, long-term fenestrated graft durability and branch vessel patency remain to be determined.

关键词： abdominal aortic aneurysm juxtarenal aneurysm endovascular aortic repair, fenestrated stent-graft

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Improved Variable Forgetting Factor Proportionate RLS Algorithm with Sparse Penalty and Fast Implementation Using DCD Iterations

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China Communications 2024年第10期21卷 16-27页

作者： Han Zhen zhang Fengrui zhang Yu Han Yanfeng Jiang peng GNSS Research Center Wuhan UniversityWuhan 430072China School of Information Science and Technology Shijiazhuang Tiedao UniversityShijiazhuang 050043China

The proportionate recursive least squares(PRLS)algorithm has shown faster convergence and better performance than both proportionate updating(PU)mechanism based least mean squares(LMS)algorithms and RLS algorithms with a sparse regularization *** this paper,we propose a variable forgetting factor(VFF)PRLS algorithm with a sparse penalty,e.g.,l_(1)-norm,for sparse *** reduce the computation complexity of the proposed algorithm,a fast implementation method based on dichotomous coordinate descent(DCD)algorithm is also *** results indicate superior performance of the proposed algorithm.

关键词： dichotomous coordinate descent proportionate matrix RLS sparse systems variable forgetting factor

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Room-temperature ferroelectricity in van der Waals SnP_(2)S_(6)

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Frontiers of physics 2024年第4期19卷 113-123页

作者： Chaowei He Jiantian zhang Li Gong peng Yu State Key Laboratory of Optoelectronic Materials and Technologies Guangzhou Key Laboratory of Flexible Electronic Materials and Wearable Devices Nanotechnology Research Center School of Materials Science and EngineeringSun Yat-sen UniversityGuangzhou 510275China Instrumental Analysis and Research Center Sun Yat-sen UniversityGuangzhou 510275China

Two-dimensional(2D)ferroelectric materials,which possess electrically switchable spontaneous polarization and can be easily integrated with semiconductor technologies,is of utmost importance in the advancement of high-integration low-power *** the experimental discovery of certain 2D ferroelectric materials such as CuInP2S6 and In2Se3,achieving stable ferroelectricity at room temperature in these materials continues to present a significant ***,stable ferroelectric order at room temperature in the 2D limit is demonstrated in van der Waals SnP_(2)S_(6) atom layers,which can be fabricated via mechanical exfoliation of bulk SnP_(2)S_(6) *** polarization is observed in thin SnP_(2)S_(6) of~7 ***,a van der Waals ferroelectric field-effect transistor(Fe-FET)with ferroelectric SnP_(2)S_(6) as top-gate insulator and ptype WTe0.6Se1.4 as the channel was designed and fabricated successfully,which exhibits a clear clockwise hysteresis loop in transfer characteristics,demonstrating ferroelectric properties of SnP_(2)S_(6) atomic *** addition,a multilayer graphene/SnP_(2)S_(6)/multilayer graphene van der Waals vertical heterostructure phototransistor was also fabricated successfully,exhibiting improved optoelectronic performances with a responsivity(R)of 2.9 A/W and a detectivity(D)of 1.4×10^(12) *** results show that SnP_(2)S_(6) is a promising 2D ferroelectric material for ferroelectric-integrated low-power 2D devices.

关键词： two-dimensional ferroelectric materials ferroelectric fieldeffect transistors photodetectors

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Early peripheral perfusion index predicts 28-day outcome in patients with septic shock

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World Journal of Emergency Medicine 2024年第5期15卷 372-378页

作者： Cheng Chi Hao Gong Kai Yang peng peng Xiaoxia zhang Department of Emergency Peking University People's HospitalBeijing 100044China Department of Emergency Intensive Care Unit the First Affi liated Hospital of Xinjiang Medical UniversityUrumqi 830000China

BACKGROUND:To investigate the prognostic value of the peripheral perfusion index(PPI)in patients with septic ***:This prospective cohort study,conducted at the emergency intensive care unit of Peking University People's Hospital,recruited 200 patients with septic shock between January 2023 and August *** patients were divided into survival(n=84)and death(n=116)groups based on 28-day *** evaluations included laboratory tests and clinical scores,with lactate and PPI values assessed upon admission to the emergency room and at 6 h and 12 h after *** factors associated with mortality were analyzed using univariate and multivariate Cox regression *** operator characteristic(ROC)curve was used to assess predictive *** rates were compared,and Kaplan-Meier survival plots were ***:Compared to the survival group,patients in the death group were older and had more severe liver damage and coagulation dysfunction,necessitating higher norepinephrine doses and increased fl uid *** lactate levels and lower PPI levels at 0 h,6 h,and 12 h were observed in the death *** Cox regression identifi ed prolonged prothrombin time(PT),decreased 6-h PPI and 12-h PPI as independent risk factors for *** area under the curves for 6-h PPI and 12-h PPI were 0.802(95%CI 0.742-0.863,P<0.001)and 0.945(95%CI 0.915-0.974,P<0.001),respectively,which were superior to Glasgow Coma Scale(GCS),Sequential Organ Failure Assessment(SOFA)scores(0.864 and 0.928).Cumulative mortality in the low PPI groups at 6 h and 12 h was signifi cantly higher than in the high PPI groups(6-h PPI:77.52%vs.22.54%;12-h PPI:92.04%vs.13.79%,P<0.001).CONCLUSION:PPI may have value in predicting 28-day mortality in patients with septic shock.

关键词： Peripheral perfusion index Septic shock Prognosis Predictive value

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Divergent contributions of spring and autumn photosynthetic phenology to seasonal carbon uptake of subtropical vegetation in China

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Journal of Geographical Sciences 2024年第7期34卷 1280-1296页

作者： peng Ying LI peng ZHOU Xiaolu LUO Yunpeng zhang Cicheng WANG Longjun LI Tong peng Changhui School of Geographic Sciences Hunan Normal UniversityChangsha410081China Department for Biogeochemical Integration Max-Planck-Institute for BiogeochemistryJena07745Germany Department of Biology Sciences Institute of Environment SciencesUniversity of Quebec at MontrealC.P.8888Succ.Centre-VilleMontrealH3C 3P8Canada

Phenological changes play a central role in regulating seasonal variation in the ecological processes,exerting significant impacts on hydrologic and nutrient cycles,and ultimately influencing ecosystem functioning such as carbon ***,the potential impact mechanisms of phenological events on seasonal carbon dynamics in subtropical regions are *** knowledge gaps hinder from accurately linking photosynthetic phenology and carbon sequestration *** chlorophyll fluorescence remote sensing and productivity data from 2000 to 2019,we found that an advancement in spring phenology increased spring gross(GPP)and net primary productivity(NPP)in subtropical vegetation of China by 2.1 gC m^(-2)yr^(-1)and 1.4 gC m^(-2)yr^(-1),respectively.A delay in autumn phenology increased the autumnal GPP and NPP by 0.4 gC m^(-2)yr^(-1)and 0.2 gC m^(-2)yr^(-1),***,the contribution of the spring phenology to spring carbon uptake increased significantly during the study period,while this positive contribution showed a nonsignificant trend in *** comparison,the later autumn phenology could significantly contribute to the increase in autumnal carbon uptake;however,this contributing effect was *** analysis indicated that these phenomena have been caused by the increased leaf area and enhanced photosynthesis due to earlier spring and later autumn phenology,*** results demonstrate the diverse impacts of vegetation phenology on the seasonal carbon sequestration ability and it is imperative to consider such asymmetric effects when modeling ecosystem processes parameterized under future climate change.

关键词： subtropics vegetation phenology remote sensing carbon cycle climate change

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The Rate of Convergence of Augmented Lagrangian Method for Minimax Optimization Problems with Equality Constraints

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Journal of the Operations Research Society of China 2024年第2期12卷 265-297页

作者： Yu-hong Dai Li-Wei zhang LSEC ICMSECAMSSChinese Academy of SciencesBeijing 100190China Institute of Operations Research and Control Theory School of Mathematical SciencesDalian University of TechnologyDalian 116024China

The augmented Lagrangian function and the corresponding augmented Lagrangian method are constructed for solving a class of minimax optimization problems with equality *** prove that,under the linear independence constraint qualification and the second-order sufficiency optimality condition for the lower level problem and the second-order sufficiency optimality condition for the minimax problem,for a given multiplier vectorμ,the rate of convergence of the augmented Lagrangian method is linear with respect to||μu-μ^(*)||and the ratio constant is proportional to 1/c when the ratio|μ-μ^(*)||/c is small enough,where c is the penalty parameter that exceeds a threshold c_(*)>O andμ^(*)is the multiplier corresponding to a local ***,we prove that the sequence of multiplier vectors generated by the augmented Lagrangian method has at least Q-linear convergence if the sequence of penalty parameters(ck)is bounded and the convergence rate is superlinear if(ck)is increasing to ***,we use a direct way to establish the rate of convergence of the augmented Lagrangian method for the minimax problem with a quadratic objective function and linear equality constraints.

关键词： Minimax optimization Augmented Lagrangian method Rate of convergence Second-order sufficiency optimality

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Heterogeneous data-driven aerodynamic modeling based on physical feature embedding

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Chinese Journal of Aeronautics 2024年第3期37卷 1-6页

作者： Weiwei zhang Xuhao peng Jiaqing KOU Xu WANG School of Aeronautics Northwestern Polytechnical UniversityXi’an 710072China Institute of Aerodynamics RWTH Aachen UniversityAachen 52062Germany

Aerodynamic surrogate modeling mostly relies only on integrated loads data obtained from simulation or experiment,while neglecting and wasting the valuable distributed physical information on the *** make full use of both integrated and distributed loads,a modeling paradigm,called the heterogeneous data-driven aerodynamic modeling,is *** essential concept is to incorporate the physical information of distributed loads as additional constraints within the end-to-end aerodynamic *** heterogenous data,a novel and easily applicable physical feature embedding modeling framework is *** framework extracts lowdimensional physical features from pressure distribution and then effectively enhances the modeling of the integrated loads via feature *** proposed framework can be coupled with multiple feature extraction methods,and the well-performed generalization capabilities over different airfoils are verified through a transonic *** with traditional direct modeling,the proposed framework can reduce testing errors by almost 50%.Given the same prediction accuracy,it can save more than half of the training ***,the visualization analysis has revealed a significant correlation between the discovered low-dimensional physical features and the heterogeneous aerodynamic loads,which shows the interpretability and credibility of the superior performance offered by the proposed deep learning framework.

关键词： Transonic flow Data-driven modeling Feature embedding Heterogenous data Feature visualization

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Stable hydrogen isoscape in precipitation generated using data fusion for East China

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Science China Earth Sciences 2024年第9期67卷 2972-2988页

作者： Jiacheng CHEN Jie CHEN Xunchang John zhang Peiyi peng State Key Laboratory of Water Resources Engineering and Management Wuhan UniversityWuhan 430072China Hubei Key Laboratory of Water System Science for Sponge City Construction Wuhan UniversityWuhan 430072China USDA-ARS Oklahoma and Central Plains Agricultural Research Center El Reno OK 73036USA Southwest Research Institute for Hydraulic and Water Transport Engineering Chongqing Jiaotong UniversityChongqing 400016China

The stable hydrogen isotope in precipitation is an effective environmental tracer for climatic and hydrologic ***,accurate and high-precision precipitation hydrogen isoscapes are currently unavailable in *** this study,a data fusion method based on Convolutional Neural Networks(CNN)is used to fuse the hydrogen isotopic composition(δ^(2)H_(p))of observations and isotope-equipped general circulation model(iGCM)simulations.A precipitation hydrogen isoscape with a temporal resolution of monthly and a spatial resolution of 50-60 km is established for East China for the 1969-2017 *** to building the isoscape,the performance of three data fusion methods(DFMs)and two bias correction methods(BCMs)is *** results indicate that the CNN fusion method performs the best with a correlation coefficient larger than 0.90 and root mean square error smaller than 10.5‰ when using observation as a *** fusion methods based on back propagation and long short-term memory neural network perform similarly,while slightly outperforming the bias correction ***,the CNN method is used to generate the hydrogen isoscape,and the temporal and spatial distribution characteristics of the hydrogen isotope in precipitation are analyzed based on this *** generated isoscape shows similar spatial and temporal distribution characteristics to *** general,the distribution pattern of δ^(2)H_(p) is consistent with the temperature effect in northern China,and consistent with the precipitation amount effect in southern *** trend of the δ^(2)H_(p) time series is consistent with that of observed precipitation and ***,the generated isoscape effectively reproduces the observations,and has the characteristics of time continuity and relative spatial regularity,which can provide valuable data support for tracking atmospheric and hydrological processes.

关键词： Precipitation Precipitation isotope General circulation model Data fusion Dataset

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Research on the Asymmetric Effect of Fixed-Asset Investment on China's Primary Energy Production in the Context of Energy Transformation

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Journal of Systems Science & Complexity 2024年第3期37卷 1163-1183页

作者： CHAI Jian HE peng zhang Xiaokong HOU Yamin School of Economics and Management Xidian UniversityXi'an 710126China

Under China’s“Dual Carbon”target(DCT),“clean replacement”on the energy supply side and“electric energy replacement”on the energy consumption side are the ways to achieve energy ***,energy projects have a long construction period,complex technology categories,and investment risks that greatly affect the development of energy *** judging the effect of investment changes on primary energy production is of great practical significance to the realization of the *** on this,NARDL and TVP-SV-VAR models are innovatively used to reveal the nonlinear effect of fixed-asset investment on China’s primary energy *** results show that the marginal effect of investment growth on coal production is about 1.44 times that of investment ***,the marginal effect of oil and gas investment growth is about 1.21times that of investment *** to the influence of resource constraints,China’s traditional fossil energy still has varying degrees of path dependence on the investment-driven development *** non-fossil energy,investment in hydropower and nuclear power has an inverse correlation with the change in *** marginal efficiency and diseconomies of scale have hindered the development of the hydropower and nuclear power *** addition,the asymmetric effect is not yet significant for the short development time and technical constraints of wind and solar *** the impulse response results,the impact curves of investment in wind and solar power are generally positive,and investment has different degrees of time-delay and time-varying effects on various energy production,which verifies the heterogeneity of investment adjustment mechanisms in different energy industries.

关键词： "Dual Carbon"target fixed-asset investment primary energy NARDL nonlinearity

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