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A unified pre-training and adaptation framework for combinatorial optimization on graphs

Science China Mathematics 2024年第6期67卷 1439-1456页

作者： Ruibin zeng Minglong Lei Lingfeng Niu lan Cheng School of Computer Science and Technology University of Chinese Academy of SciencesBeijing100049China Faculty of Information Technology Beijing University of TechnologyBeijing100124China School of Economics and Management University of Chinese Academy of SciencesBeijing100190China School of Mathematics and Statistics Central South UniversityChangsha410075China

Combinatorial optimization(CO)on graphs is a classic topic that has been extensively studied across many scientific and industrial fields.Recently,solving CO problems on graphs through learning methods has attracted great attention.Advanced deep learning methods,e.g.,graph neural networks(GNNs),have been used to effectively assist the process of solving COs.However,current frameworks based on GNNs are mainly designed for certain CO problems,thereby failing to consider their transferable and generalizable abilities among different COs on graphs.Moreover,simply using original graphs to model COs only captures the direct correlations among objects,which does not consider the mathematical logicality and properties of COs.In this paper,we propose a unified pre-training and adaptation framework for COs on graphs with the help of the maximum satisfiability(Max-SAT)problem.We first use Max-SAT to bridge different COs on graphs since they can be converted to Max-SAT problems represented by standard formulas and clauses with logical information.Then we further design a pre-training and domain adaptation framework to extract the transferable and generalizable features so that different COs can benefit from them.In the pre-training stage,Max-SAT instances are generated to initialize the parameters of the model.In the fine-tuning stage,instances from CO and Max-SAT problems are used for adaptation so that the transferable ability can be further improved.Numerical experiments on several datasets show that features extracted by our framework exhibit superior transferability and Max-SAT can boost the ability to solve COs on graphs.

关键词： combinatorial optimization graph neural networks domain adaptation maximum satisfiability problem

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Pulmonary rehabilitation protocols in urgent lung transplantation patients

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World Journal of Emergency Medicine 2024年第1期15卷 47-51页

作者： Fei zeng Lingyun Cai Luyao Guo Meijuan lan Jiangshuyuan Liang Peipei Gu Nursing Department the Second Affi liated Hospital of Zhejiang University School of MedicineHangzhou 310009China

BACKGROUND:Prolonged invasive respiratory support and extracorporeal membrane oxygenation(ECMO)in patients requiring urgent lung transplantation(ULTx)present signifi cant challenges to clinical practice due to severe underlying diseases and complex conditions.The aim of the study was to report the clinical outcomes of patients who received ULTx and followed the perioperative rehabilitation protocol implemented in a lung transplant center.METHODS:A retrospective analysis was conducted in ULTx patients who required preoperative invasive mechanical ventilation(IMV)and ECMO between January 2018 and January 2023.Data were retrieved from electronic medical records at our lung transplant center.RESULTS:Fourteen patients(mean age 57.43±10.97 years;12 males,2 females)underwent ULTx with bridging ECMO and IMV.The mean body mass index was 23.94±3.33 kg/m²,and the mean Acute Physiology and Chronic Health Evaluation(APACHE)II score was 21.50±3.96.The Nutritional Risk Screening 2002(NRS 2002)scores were≥3.ULTx was performed after an 8.5-day waiting period(interquartile interval[IQR]5.0-26.5 d).Following the surgeries,the average lengths of ECMO and IMV were 1.0(IQR 1.0-2.0)d and 5.0(IQR 3.0-7.3)d,respectively.The total length of hospital stay was 60.1±30.8 d,with an average intensive care unit stay of 38.3±22.9 d and post-operative hospitalization stay of 45.8±26.1 d.Two patients died within 30 d after ULTx,with a 30-day survival rate of 85.71%.CONCLUSION:Patients receiving ULTx showed an acceptable short-term survival rate,validating the practicality and safety of the treatment protocols implemented in our center.

关键词： Urgent lung transplantation End-stage lung disease Extracorporeal membrane oxygenation Invasive respiratory support Pulmonary rehabilitation.

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Placenta-derived mesenchymal stem cells attenuate secondary brain injury after controlled cortical impact in rats by inhibiting matrix metalloproteinases

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BIOCELL 2024年第1期48卷 149-162页

作者： PING YANG YUANXIANG lan ZHONG zeng YAN WANG HECHUN XIA Department of Neurosurgery School of Clinical MedicineNingxia Medical UniversityYinchuanChina Key Laboratory of Ningxia Stem Cell and Regenerative Medicine General Hospital of Ningxia Medical UniversityYinchuanChina Department of Neurosurgery Xi’an International Medical Center HospitalXi’anChina

Background:As a form of biological therapy,placenta-derived mesenchymal stem cells(PDMSCs)exhibit considerable promise in addressing the complex pathological processes of traumaticbrain injury(TBI)due to their multi-target and multi-pathway mode of action.Material&Methods:This study investigates the protective mechanisms and benefits of PDMSCs in mitigating the effects of controlled cortical impact(CCI)in rats and glutamate-induced oxidative stress injury in HT22 cells in vitro.Our primary objective is to provide evidence supporting the clinical application of PDMSCs.Results:In the in vivo arm of our investigation,we observed a swift elevation of matrix metalloproteinase-9(MMP-9)in the proximal cortex of injured brain tissues after CCI.PDMSCs,distinguished by their heightened expression of metalloproteinase tissue inhibitors-1 and-2(TIMP-1 and TIMP-2):were intravenously administered via the caudal vein.This intervention yielded significant reductions in the permeability of the blood-brain barrier(BBB):the extent of brain edema,the levels of inflammatory cytokines IL-1βand TNF-αin damaged brain tissue,and the activation status of microglia in CCI-afflicted rats.In the realm of in vitro experiments,PDMSC-conditioned media demonstrated substantial reductions in mortality rates and cleaved caspase-3 levels in glutamate-induced HT22 cells compared with conventional media.Notably,this advantage was negated upon the introduction of neutralizing antibodies targeting TIMP-1 and TIMP-2.Conclusion:Collectively,our findings underscore the potential of PDMSCs in alleviating oxidative stress injury and secondary brain injury in the pathological process of TBI.

关键词： Traumatic brain injury Mesenchymal stem cells Oxidative stress Matrix metalloproteinases

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Interface Design Strategy for GNS/AZ91 Composites with Semi-Coherent Structure

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Acta Metallurgica Sinica(English Letters) 2024年第3期37卷 467-483页

作者： Jing-Peng Xiong Yi-Qi zeng Jin-Long Liu Wei-Cheng Wang lan Luo Yong Liu Key Laboratory of Lightweight and High Strength Structural Materials of Jiangxi Province School of Advanced ManufacturingNanchang UniversityNanchang 330031China School of Physics and Materials Science Nanchang UniversityNanchang 330031China

The interfacial structure plays an important role in the mechanical properties of magnesium matrix composite(MMCs)reinforced with graphene nanosheet(GNS)due to their poor wettability with the Mg matrix.An interface design strategy was proposed to form the semi-coherent interfacial structure with superior bonding strength.The lattice mismatch and interfacial bonding strength between Mg/rare earth oxide/carbon were utilized as key characteristics to evaluate the interfacial structure.lanthanum oxide(La2O3)was selected as the intermediate candidate due to its low lattice mismatch and high interfacial bonding strength.To identify the interfacial structure of Mg/La2O3/graphene,first-principles calculations were conducted to calculate the ideal work of separation and electronic structure of the interfaces.Results demonstrated the presence of strong ionic and covalent interactions at the interface,which theoretically verified the strong interfacial bonding strength among Mg/La2O3/graphene interfaces.To experimentally validate the interface strength,MMCs with the interface structure of Mg/La2O3/GNS were developed.The formation of in-situ La2O3 led to the successful attainment of semi-coherent structures between Mg/La2O3 and La2O3/GNS,resulting in high strength and good ductility of the composite.Overall,this work proposes a new approach to interface design in MMCs with an enhancement of mechanical properties.

关键词： Interface design strategy Magnesium matrix composite Graphene nanosheets Semi-coherent interface Mechanical properties

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Tailoring crystallization zinc hydroxide sulfates growth towards stable zinc deposition chemistry

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Nano Research 2024年第6期17卷 5243-5250页

作者： Kaixin Huang Xianguang zeng Dan Zhang Yujie Wang Mu lan Chengyan Wen Yi Guo College of Materials Science and Engineering Sichuan University of Science and EngineeringZigong 643000China Department of Chemistry College of Resource and EnvironmentBaoshan UniversityBaoshan 678000China College of Optoelectronic Engineering Chengdu University of Information TechnologyChengdu 610225China

The unstable zinc anode/electrolyte interface induced by corrosion,interfacial water splitting reaction,and dendrite growth seriously degrades the performances of metal Zn anode in aqueous electrolyte.Herein,the nucleation and growth of zinc hydroxide sulfate(ZHS),an interfacial by-product,has been tailored by Tween 80 in the electrolyte,which thereby assists in in-situ forming a dense solid electrolyte interphase(SEI)with small-sized ZHS and evenly distributed Tween 80.This SEI has high corrosion resistance and uniform distribution of zinc ions,which not only contributes to blocking the interfacial side reactions but also induces stable and calm zinc plating/stripping.Consequently,the modified electrolyte can confer the assembled Zn||Zn symmetric cell with a stable operation life over 1500 h at 1 mA·cm^(−2)and 1 mAh·cm^(−2)as well as the practical Zn||NH4V4O10 full battery with a high-rate capacity of 120 mAh·g^(−1)at the current density of 5 A·g^(−1).This work provides a way for regulating and reusing interfacial by-products,and a new sight on stabilization electrodes/electrolyte interfaces.

关键词： zinc hydroxide sulfides tailoring crystallization in-situ solid electrolyte interphase electrolyte engineering strategy aqueous zinc-ion battery

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Deep reinforcement learning using least-squares truncated temporal-difference

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CAAI Transactions on Intelligence Technology 2024年第2期9卷 425-439页

作者： Junkai Ren Yixing lan Xin Xu Yichuan Zhang Qiang Fang Yujun zeng College of Intelligence Science and Technology National University of Defense TechnologyChangshaChina State Key Laboratory of Astronautic Dynamics Xi'an Satellite Control CenterXi'anChina

Policy evaluation(PE)is a critical sub-problem in reinforcement learning,which estimates the value function for a given policy and can be used for policy improvement.However,there still exist some limitations in current PE methods,such as low sample efficiency and local convergence,especially on complex tasks.In this study,a novel PE algorithm called Least-Squares Truncated Temporal-Difference learning(LST2D)is proposed.In LST2D,an adaptive truncation mechanism is designed,which effectively takes advantage of the fast convergence property of Least-Squares Temporal Difference learning and the asymptotic convergence property of Temporal Difference learning(TD).Then,two feature pre-training methods are utilised to improve the approximation ability of LST2D.Furthermore,an Actor-Critic algorithm based on LST2D and pre-trained feature representations(ACLPF)is proposed,where LST2D is integrated into the critic network to improve learning-prediction efficiency.Comprehensive simulation studies were conducted on four robotic tasks,and the corresponding results illustrate the effectiveness of LST2D.The proposed ACLPF algorithm outperformed DQN,ACER and PPO in terms of sample efficiency and stability,which demonstrated that LST2D can be applied to online learning control problems by incorporating it into the actor-critic architecture.

关键词： Deep reinforcement learning policy evaluation temporal difference value function approximation

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Evaluation of the binding affinity and antioxidant activity of phlorizin to pepsin and trypsin

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Food Science and Human Wellness 2024年第1期13卷 392-400页

作者： Jing Zhang lan Tang Xia Hu Zhen zeng Wen Wu Fang Geng Hui Li Di Wu Meat Processing Key Laboratory of Sichuan Province School of Food and Biological EngineeringChengdu UniversityChengdu 610106China School of Chemical Engineering Sichuan UniversityChengdu 610065China

Phlorizin(PHL)is a natural compound with strong antioxidant properties mainly found in apples.In this paper,the interaction mechanism of PHL with pepsin and trypsin was comparatively evaluated by computer simulation,fluorescence spectra,circular dichroism(CD),and Fourier transform infrared(FT-IR)spectra at a molecular level.Fluorescence spectra showed that PHL quenches the pepsin/trypsin by static quenching.Thermodynamic parameters indicated that PHL binds to pepsin mainly through hydrogen bonds and van der Waals forces,and that of trypsin was electrostatic forces.The ground state complexes PHL and protease have a moderate affinity of 105 L/mol PHL binds more strongly to trypsin than to pepsin.CD and FT-IR spectra results showed that pepsin/trypsin decreased theβ-sheet content and slightly changed its secondary structure upon PHL.These experimental results are mutually verified with the predicted computer-aid simulation results.Upon PHL and trypsin binding,the antioxidant capacity of PHL was elevated.Nevertheless,the antioxidant capacity of PHL was decreased after binding to pepsin.This work elucidates the binding of PHL binding mechanisms to pepsin/trypsin and provides useful information for the digestion of PHL to improve the application of PHL in food processing.

关键词： Interaction Phlorizin Pepsin Trypsin Antioxidation

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Plasma metabolites and risk of myocardial infarction:a bidirectional Mendelian randomization study

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Journal of Geriatric Cardiology 2024年第2期21卷 219-231页

作者： Dong-Hua LI Qiang WU Jing-Sheng lan Shuo CHEN You-Yi HUANG lan-Jin WU Zhi-Qing QIN Ying HUANG Wan-Zhong HUANG Ting zeng Xin HAO Hua-Bin SU Qiang SU Department of Cardiovascular Medicine Minzu Hospital of Guangxi Zhuang Autonomous RegionGuangxiChina Senior Department of Cardiology the Sixth Medical CenterChinese PLA General HospitalBeijingChina Library of Graduate School Chinese PLA General HospitalBeijingChina Department of Cardiology Jiangbin Hospital of Guangxi Zhuang Autonomous RegionGuangxiChina Health Management Institute the Second Medical CenterChinese PLA General HospitalBeijingChina

BACKGROUND Myocardial infarction(MI)is a critical cardiovascular event with multifaceted etiology,involving several genetic and environmental factors.It is essential to understand the function of plasma metabolites in the development of MI and unravel its complex pathogenesis.METHODS This study employed a bidirectional Mendelian randomization(MR)approach to investigate the causal relationships between plasma metabolites and MI risk.We used genetic instruments as proxies for plasma metabolites and MI and conducted MR analyses in both directions to assess the impact of metabolites on MI risk and vice versa.In addition,the large-scale genome-wide association studies datasets was used to identify genetic variants associated with plasma metabolite(1400 metabolites)and MI(20,917 individuals with MI and 440,906 individuals without MI)susceptibility.Inverse variance weighted was the primary method for estimating causal effects.MR estimates are expressed as beta coefficients or odds ratio(OR)with 95%CI.RESULTS We identified 14 plasma metabolites associated with the occurrence of MI(P<0.05),among which 8 plasma metabolites[propionylglycine levels(OR=0.922,95%CI:0.881–0.965,P<0.001),gamma-glutamylglycine levels(OR=0.903,95%CI:0.861–0.948,P<0.001),hexadecanedioate(C16-DC)levels(OR=0.941,95%CI:0.911–0.973,P<0.001),pentose acid levels(OR=0.923,95%CI:0.877–0.972,P=0.002),X-24546 levels(OR=0.936,95%CI:0.902–0.971,P<0.001),glycine levels(OR=0.936,95%CI:0.909–0.964,P<0.001),glycine to serine ratio(OR=0.930,95%CI:0.888–0.974,P=0.002),and mannose to trans-4-hydroxyproline ratio(OR=0.912,95%CI:0.869–0.958,P<0.001)]were correlated with a decreased risk of MI,whereas the remaining 6 plasma metabolites[1-palmitoyl-2-arachidonoyl-GPE(16:0/20:4)levels(OR=1.051,95%CI:1.018–1.084,P=0.002),behenoyl dihydrosphingomyelin(d18:0/22:0)levels(OR=1.076,95%CI:1.027–1.128,P=0.002),1-stearoyl-2-docosahexaenoyl-GPE(18:0/22:6)levels(OR=1.067,95%CI:1.027–1.109,P=0.001),alpha-ketobutyrate levels(OR=1.108,95%CI:1.041–1.180,P=0.001),5-acetylamino-6-formylam

关键词： infarction alterations diagnosis

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Highly Transparent Fire-resistant Coatings with Intumescent Three-source Integration

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Chinese Journal of Polymer Science 2024年第7期42卷 907-915,I0005页

作者： Xiao-Liang zeng Xin-Sheng lan Yan Wang Lin Zhang De-Ming Guo Hai-Bo Zhao State Grid Sichuan Electric Power Research Institute Chengdu610041China The Collaborative Innovation Center for Eco-Friendly and Fire-Safety Polymeric Materials(Ministry of Education) National Engineering Laboratory of Eco-Friendly Polymeric Materials(Sichuan)State Key Laboratory of Polymer Materials EngineeringCollege of ChemistrySichuan UniversityChengdu610064China

Wood,a readily available and sustainable natural resource,has found widespread use in construction and furniture.However,its inherent flammability poses a potential fire risk.Although intumescent fire-retardant coatings effectively mitigate this risk,achieving high transparency in such coatings presents a significant challenge.In our approach,we employed a cross-linked network of phytic acid anion and N-[3-(trimethoxysilyl)propyl]-N,N,N-trimethylammonium cation to create a transparent"three-in-one"intumescent coating.The collaborative P/N/Si flame-retardant effect markedly improved the intumescent char-forming capability,preventing the wood from rapid decomposition.This resulted in a substantial reduction in heat release(13.9%decrease in THR)and an increased limiting oxygen index(LOI)value of 35.5%.Crucially,the high transparency of the coating ensured minimal impact on the wood's appearance,allowing the natural wood grains to remain clearly visible.This innovative approach provides a straightforward method for developing transparent intumescent flame-retardant coatings suitable for wooden substrates.The potential applications extend to preserving ancient buildings and heritage conservation efforts.

关键词： Fire-resistant coating Flame retardancy Wood Transparency

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Lipase and photodecarboxylase coexpression: A potential strategy for alkane-based biodiesel production from natural triglycerides

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Chinese Journal of Chemical Engineering 2024年第3期67卷 238-246页

作者： Yong-Yi zeng Xin-Yi Xu Jin-Xuan Xie Wen-Li Chen lan Liu Xin-Jian Yin Bi-Shuang Chen School of Marine Sciences Sun Yat-Sen UniversityZhuhai 519080China Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai) Zhuhai 519080China

Alkane-based biodiesel is considered the next generation of biodiesel owing to its potential environmental benefits and the fact that it exhibits much higher specific caloric values than traditional biodiesel.However,the formidable obstacle impeding the commercialization of this cutting-edge fuel alternative lies in the cost associated with its production.In this study,an engineered strain Escherichia coli(E.coli)showcasing harmonized coexpression of a lipase(from Thermomyces lanuginosus lipase,TLL)and a fatty acid photodecarboxylase(from Chlorella variabilis,CvFAP)was first constructed to transform triglycerides into alkanes.The potential of E.coli BL21(DE3)/pRSFDuet-1-TLL-CvFAP for alkane synthesis was evaluated with tripalmitin as a model substrate under various process conditions.Following a comprehensive examination of the reaction parameters,the scope of the biotransformation was expanded to‘real’substrates(vegetable oils).The results showed that bioderived oils can be transformed into alkanes with high yields(0.80-10.20 mmol·L^(-1))under mild conditions(35℃,pH 8.0,and 36 h)and blue light illumination.The selected processes were performed on an increased lab scale(up to 100 ml)with up to 24.77 mmol·L^(-1) tripalmitin,leading to a yield of 18.89 mmol·L^(-1) pentadecane.With the employment of a method for efficiently producing alkanes under mild conditions and a simple procedure to isolate alkanes from the reaction system,the utilization of sustainable biomass as a fundamental feedstock emerges as the primary solution to lower the cost of alkane-based biodiesel.Thus,this study proposes a readily implementable and highly effective approach for alkane-based biodiesel production.

关键词： Alkane-based biodiesel Renewable biomass Co-overexpression Lipase Photodecarboxylase

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