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Prone position ventilation in severe acute pancreatitis patients with concurrent acute respiratory distress syndrome and abdominal compartment syndrome:a case report
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作者 Jiaping Yu Yun Ji Haifei Lu 《World Journal of Emergency Medicine》 2026年第1期98-100,共3页
Severe acute pancreatitis(SAP)can induce acute respiratory distress syndrome(ARDS)and abdominal compartment syndrome(ACS).Although prone position ventilation(PPV)can improve outcomes in patients with ARDS,there is sig... Severe acute pancreatitis(SAP)can induce acute respiratory distress syndrome(ARDS)and abdominal compartment syndrome(ACS).Although prone position ventilation(PPV)can improve outcomes in patients with ARDS,there is significant controversy regarding its concurrent use with ACS owing to concerns of increased risk of intra-abdominal pressure(IAP).[1]We present a case of successful PPV application without adverse eff ects. 展开更多
关键词 severe acute pancreatitis sap can prone position ventilation ppv can acute respiratory distress syndrome abdominal compartment syndrome abdominal compartment syndrome acs prone position ventilation intra abdominal pressure acute respiratory distress syndrome ards
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Curvilinear Supine Position for Pressure Injury Prevention in Pediatric Cardiac Surgery Patients:A Randomized Controlled Trial
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作者 Qianxue Yang Xiuli Xiao +2 位作者 Minzhe Xing Shuo Qin Xian Li 《Journal of Clinical and Nursing Research》 2026年第1期345-353,共9页
Background:Pressure injury(PI)is a prevalent complication in pediatric cardiac surgery,with higher incidence than in general pediatric populations due to children’s thin skin,underdeveloped subcutaneous tissue,and pr... Background:Pressure injury(PI)is a prevalent complication in pediatric cardiac surgery,with higher incidence than in general pediatric populations due to children’s thin skin,underdeveloped subcutaneous tissue,and prolonged intraoperative pressure.Objective:To evaluate the effectiveness of the curvilinear supine position(CSP)in preventing PI among children undergoing congenital heart disease(CHD)surgery.Methods:Between October 2024 and February 2025,a single-center randomized controlled trial was conducted.Of the 80 children initially enrolled for congenital heart disease(CHD)surgery,77(aged 1 month to 14 years)completed the study and were included in the final analysis after 3 were excluded due to protocol violations.Participants were randomly assigned to the CSP group(n=38)or the conventional supine position group(n=39).Results:The incidence of PI was significantly lower in the CSP group(2.6%)compared to the control group(20.5%)(p=0.029).Postoperative LDH levels were also significantly reduced in the CSP group(422.67±86.52 U/L vs.592.92±215.71 U/L;p=0.031),while preoperative LDH and surgical variables(e.g.,cardiopulmonary bypass time)were comparable between groups.Although the CSP group had a shorter hospital stay(17.24 vs.22.51 days),the difference was not statistically significant(p=0.085).Caregiver satisfaction was significantly higher in the CSP group(100.0%vs.84.6%;p=0.025).Conclusion:CSP effectively reduces PI incidence,mitigates tissue injury,and enhances caregiver satisfaction in pediatric cardiac surgery,offering a safe and feasible strategy for perioperative PI prevention. 展开更多
关键词 Curvilinear supine position Pressure injury CHILDREN Perioperative nursing Cardiac surgery
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Workspace-based hybrid force position posture alignment for high quality aircraft assembly of large-scale components
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作者 Yajun LI Wei LIU +4 位作者 Hu LU Runze LIU Changyong GAO Qihang CHEN Yang ZHANG 《Chinese Journal of Aeronautics》 2026年第1期553-569,共17页
The high-quality assembly of Large Aircraft Components(LACs)is essential in modern aviation manufacturing.Numerical control locators are employed for the posture adjustment of LAC,yet the system's multi-input mult... The high-quality assembly of Large Aircraft Components(LACs)is essential in modern aviation manufacturing.Numerical control locators are employed for the posture adjustment of LAC,yet the system's multi-input multi-output,nonlinearity,and strong coupling presents significant challenges.The substantial internal force generated during the adjustment process can potentially damage the LAC and degrade the assembly quality.Hence,a workspace-based hybrid force position control scheme was developed to achieve high quality assembly with high-precision and lower internal force.Firstly,an offline workspace analysis with inherent geometric characteristics to form time-varying posture error constraint.Then,the posture error is integrated into the online position axis control to ensure tracking the ideal posture,while the force control axis compensates for posture deviation by minimizing internal force,thereby achieving high precision and low internal force.Finally,the effectiveness was demonstrated through experiments.The root mean square errors of orientation and position are 104 rad and 0.1 mm,respectively.A reduction in internal force can range from 10.96%to 57.4%compared to the traditional method.Key points'max position error is decreased from 0.32 mm to 0.18 mm,satisfying the 0.5 mm tolerance.Therefore,the proposed method will help promote the development of high-performance manufacturing. 展开更多
关键词 Aircraft manufacture Posture alignment Hybrid constraints Workspace analysis Hybrid force position control Internal force
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An explainable deep learning approach to enhance the prediction of shield tunnel deviation
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作者 Jiajie Zhen Fengwen Lai +4 位作者 Ming Huang Junjie Zheng Jim S.Shiau Ping Wang Jinhuo Zheng 《Journal of Rock Mechanics and Geotechnical Engineering》 2026年第1期566-579,共14页
Although machine learning models have achieved high enough accuracy in predicting shield position deviations,their“black box”nature makes the prediction mechanisms and decision-making processes opaque,leading to wea... Although machine learning models have achieved high enough accuracy in predicting shield position deviations,their“black box”nature makes the prediction mechanisms and decision-making processes opaque,leading to weaker explanations and practicability.This study introduces a novel explainable deep learning framework comprising the Informer model with enhanced attention mechanisms(EAMInfor)and deep learning important features(DeepLIFT),aimed at improving the prediction accuracy of shield position deviations and providing interpretability for predictive results.The EAMInfor model attempts to integrate channel attention,spatial attention,and simple attention modules to improve the Informer model's performance.The framework is tested with the four different geological conditions datasets generated from the Xiamen metro line 3,China.Results show that the EAMInfor model outperforms the traditional Informer and comparison models.The analysis with the DeepLIFT method indicates that the push thrust of push cylinder and the earth chamber pressure are the most significant features,while the stroke length of the push cylinder demonstrated lower importance.Furthermore,the variation trends in the significance of data points within input sequences exhibit substantial differences between single and composite strata.This framework not only improves predictive accuracy but also strengthens the credibility and reliability of the results. 展开更多
关键词 Shield tunnel position deviation Machine learning Explainable AI Deep learning important features
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Postoperative effective lens position and refraction changes with three different types of intraocular lens
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作者 Xi-Xia Ding Lin-Feng Xiang +5 位作者 Wen-Tao Tong Dan-Dan Wang Hong-FangZhang Ping-Jun Chang Fu-Man Yang Yun-E Zhao 《International Journal of Ophthalmology(English edition)》 2026年第2期260-265,共6页
AIM:To evaluate and compare alterations in the effective lens position(ELP)and refractive outcomes among three distinct intraocular lens(IOL)types.METHODS:Patients with cataracts were enrolled and allocated to 3 group... AIM:To evaluate and compare alterations in the effective lens position(ELP)and refractive outcomes among three distinct intraocular lens(IOL)types.METHODS:Patients with cataracts were enrolled and allocated to 3 groups:Group A(implanted with the SN6CWS),Group B(implanted with the MI60),and Group C(implanted with the Aspira-aA).ELP measurements were obtained with swept-source optical coherence tomography(SS-OCT)at 1d,1wk,1mo,and 3mo postoperatively.Subjective refraction assessments were conducted at 1wk,1mo,and 3mo following surgery.RESULTS:The study included 189 eyes of 150 cataract patients(66 males).There were 77 eyes in Group A,55 eyes in Group B,and 57 eyes in Group C.The root mean square of the ELP(ELPRMS)within the initial 3mo was significantly lower for Group A than for Groups B and C.Refractive changes within Group A were not significant across the time points of 1wk,1mo,and 3mo.Conversely,both Group B and Group C demonstrated statistically significant shifts toward hyperopia from 1wk to 3mo postsurgery.CONCLUSION:Among the three IOLs examined,the SN6CWS IOL showes the greatest stability during the first 3mo postoperatively.Between 1wk and 3mo after surgery,notable hyperopic shifts are evident in eyes implanted with the MI60 and Aspira-aA IOLs,whereas refractive outcomes remain relatively constant in eyes implanted with SN6CWS IOLs. 展开更多
关键词 effective lens position REFRACTION intraocular lens swept-source optical coherence tomography
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Effect of fluorination positions at diphenylamino flanking groups on the photovoltaic performance for nonfused ring electron acceptors
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作者 Yang Gao Huarui Zhang +7 位作者 Yan Xie Xinjun Xu Yahui Liu Hao Lu Wenkai Zhang Yuqiang Liu Cuihong Li Zhishan Bo 《Chinese Chemical Letters》 2026年第1期368-373,共6页
The fluorination strategy has been proven effective in significantly enhancing the photovoltaic performance of organic solar cells(OSCs) based on non-fused ring electron acceptors(NFREAs).However,research on the impac... The fluorination strategy has been proven effective in significantly enhancing the photovoltaic performance of organic solar cells(OSCs) based on non-fused ring electron acceptors(NFREAs).However,research on the impact of fluorination positions at side chains on NFREAs device performance remains scant.In this study,we introduce two isomeric NFREAs,designated as GA-2F-E and GA-2F,distinguished by their fluorination positions at the side chains.Both NFREAs share a thiophene[3,2-b]thiophene core,but their side chains differ:GA-2F-E features two(4-butylphenyl)-N-(4-fluorophenyl) amino groups,whereas GA-2F's side chains consist of bis(4-fluorophenyl)amino and bis(4-butylphenyl)amino groups attached to opposite sides of the core.To delve into the influence of fluorination positions on the optoelectronic properties,aggregation behavior,and overall efficiency of the acceptor molecules,a comprehensive investigation was conducted.The findings reveal that,despite similar photophysical properties and comparable absorption bandwidths,GA-2F-E,with fluorine atoms positioned on both sides of the molecular framework,demonstrates more compact π-π stacking,reduced bimolecular recombination,superior exciton transport,and a more balanced,higher mobility.As a result of these advantages,OSCs optimized with D18:GA-2F-E achieve a remarkable power conversion efficiency(PCE) of 16.45 %,surpassing the 15.83 %PCE of devices utilizing D18:GA-2F.This research underscores the potential of NFREAs in future applications and highlights the significance of fluorination positions in enhancing OSC performance,paving the way for the development of more efficient NFREAs. 展开更多
关键词 Organic solar cells Non-fused ring electron acceptors Fluorination position Diphenylamino groups Power conversion efficiencies
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A Safe Harbour
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作者 DARYL GUPPY 《ChinAfrica》 2026年第3期20-21,共2页
The Hainan FTP is a game changer,and those who seize the opportunities it offers early will be in an advantageous position As it provides a vital new model for China’s international trade and logistics,the Hainan Fre... The Hainan FTP is a game changer,and those who seize the opportunities it offers early will be in an advantageous position As it provides a vital new model for China’s international trade and logistics,the Hainan Free Trade Port(FTP)stands out among similar opening-up initiatives. 展开更多
关键词 safe harbour free trade port game changer free trade port ftp stands advantageous position logistics opportunities international trade
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Tracheal intubation in the lateral position in emergency medicine:a narrative review and clinical protocol 被引量:2
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作者 Ping Cui Tingting Wen +4 位作者 Bingduo Wang Shuijing Wu Shiyu Chen Xiangming Fang TILP consortium 《World Journal of Emergency Medicine》 2025年第2期103-112,共10页
BACKGROUND:Tracheal intubation(TI)is a fundamental procedure for securing the airway or assisting ventilation in emergency medicine.Tracheal intubation in the lateral position(TILP)has been utilized in clinical practi... BACKGROUND:Tracheal intubation(TI)is a fundamental procedure for securing the airway or assisting ventilation in emergency medicine.Tracheal intubation in the lateral position(TILP)has been utilized in clinical practice,demonstrating potential advantages in specific scenarios,including emergency settings.However,there is a lack of comprehensive reviews and practical protocols on TILP application.To address this gap,we performed a narrative review,and provided evidence-based recommendations to formulate a practice protocol,to assist clinicians to effectively apply TILP.METHODS:We conducted a narrative review of TILP applications and developed recommendations based on clinical research evidence and clinical experience.Delphi method was used among the TILP consortium to grade the strength of the recommendations and to help reach consensus.The practice protocols were formulated as warranted by advancements in medical knowledge,technology,and practice.RESULTS:This narrative review summarized the current evidence on TILP application,highlighting its safety,efficacy,challenges,and potential complications.In total,24 recommendations and a clinical protocol for TILP application in emergency patients were established.CONCLUSION:TILP is a valuable technique in emergency medicine.We reviewed its application in emergency settings and formulated recommendations along with a clinical practice protocol.Future studies are needed to evaluate the safety and efficacy of TILP,broaden its scope of application,and explore effective training protocols. 展开更多
关键词 Tracheal intubation Lateral position Emergency medicine Critical care
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Subsoiling before winter wheat alleviates the kernel position effect of densely grown summer maize by delaying post-silking root-shoot senescence 被引量:1
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作者 Lichao Zhai Shijia Song +10 位作者 Lihua Zhang Jinan Huang Lihua Lü Zhiqiang Dong Yongzeng Cui Mengjing Zheng Wanbin Hou Jingting Zhang Yanrong Yao Yanhong Cui Xiuling Jia 《Journal of Integrative Agriculture》 2025年第9期3384-3402,共19页
The intensified kernel position effect is a common phenomenon in maize production under higher plant density,which limits crop productivity.Subsoiling is an effective agronomic practice for improving crop productivity... The intensified kernel position effect is a common phenomenon in maize production under higher plant density,which limits crop productivity.Subsoiling is an effective agronomic practice for improving crop productivity.To clarify the effect of subsoiling before winter wheat on the kernel position effect of densely grown summer maize and its regulatory mechanism,field experiments were conducted during the 2020-2021 and 2021-2022 growing seasons using a split-plot design.The main plots included two tillage practices:conventional tillage practice(CT)and subsoiling before the sowing of winter wheat(SS);and the subplots consisted of three plant densities(D1-D3 at 6.0×10~4,7.5×10~4,and 9.0×10~4 plants ha-1).Compared with CT,SS alleviated the kernel position effect by increasing the weight ratio of inferior to superior kernels(WR)in the D2 and D3 treated plants.The higher WR of SS treated plants contributed largely to the improved flling of inferior kernels.Under the same plant density,SS signifcantly improved the root dry matter accumulation(DMA)and antioxidant enzyme activities(superoxide dismutase(SOD)and peroxidase(POD)),and it reduced the malondialdehyde(MDA)content,especially for the plants grown under higher plant densities.These results indicated that SS delayed the root senescence,which is associated with the reduced soil bulk density.In addition,compared with CT,SS increased the leaf chlorophyll content from 20 days after silking to physiological maturity and the post-silking leaf area duration,and it reduced the post-silking leaf chlorophyll reduction rate and leaf area reduction rate,indicating that the post-silking leaf senescence had been alleviated.Under the same plant density,the post-silking DMA of SS was obviously higher than that of CT,which was probably related to the improved leaf area duration and photosynthetic enzyme activities(phosphoenolpyruvate carboxylase(PEPC)and Rubisco).The correlation analysis revealed that the main mechanism of SS in alleviating the kernel position effect of densely grown summer maize is as follows:SS delays the post-silking root-shoot senescence by regulating soil physical properties,and further improves the post-silking DMA and flling of inferior kernels,which ultimately alleviates the kernel position effect and improves grain yield.The results of this study provide new theoretical support for the promotion of summer maize yield by subsoiling before winter wheat. 展开更多
关键词 SUBSOILING summer maize kernel position effect SENESCENCE dry matter accumulation grain yield
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In-flight measurement method and application research of helicopter rotor blade motion parameters 被引量:1
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作者 Jiahong ZHENG Weizhen CHENG +2 位作者 Yan LI Shuaike JIAO Xide LI 《Chinese Journal of Aeronautics》 2025年第9期190-207,共18页
Accurate measurement of helicopter rotor motion parameters(flap,lead-lag,torsion,and azimuth angles)is essential for rotor blade design,helicopter dynamics modeling,and flight safety and health monitoring.However,the ... Accurate measurement of helicopter rotor motion parameters(flap,lead-lag,torsion,and azimuth angles)is essential for rotor blade design,helicopter dynamics modeling,and flight safety and health monitoring.However,the existing methods face challenges in testing equipment installation,calibration,and data transmission,resulting in limited reports on real-time in-flight measurements of blade motion parameters.This paper proposes a non-contact optoelectronic method based on two-dimensional position-sensitive detectors for in-flight measurement and a ground calibration system to obtain real-time rotor motion parameters during helicopter flight.The proposed method establishes the time evolution relationship of rotor motion parameters and verifies the performance of the in-flight measurement system regarding measurement resolution and accuracy through the construction of a blade motion posture experimental platform.The proposed method has been applied to the flight measurement of a medium-sized single-rotor helicopter,and the obtained results have been compared with theoretical analysis outcomes.Furthermore,this paper examines the characteristics of blade motion parameters during flight and discusses the challenges and potential solutions for measuring rotor motion parameters during helicopter flight using the proposed method. 展开更多
关键词 Blade motion parameters Flight test Helicopter rotors MEASUREMENT Optical instruments Position sensitive detector
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Spatio-temporal uneven distribution of soil moisture replenishment by rainfall events along a hillslope in the Liupan Mountains, Northwest China 被引量:1
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作者 BAI Yushi YU Pengtao +4 位作者 WAN Yanfang LIU Bingbing WANG Yanhui LIU Zebin Ashley A.WEBB 《Journal of Mountain Science》 2025年第4期1376-1387,共12页
Mountainous areas are the priority for forest restoration in semiarid regions,with hillslopes serving as the basic units of mountains.Precipitation is the only water source in these regions,and the uneven distribution... Mountainous areas are the priority for forest restoration in semiarid regions,with hillslopes serving as the basic units of mountains.Precipitation is the only water source in these regions,and the uneven distribution of hillslope soil moisture replenishment after precipitation determines vegetation survival and growth.Therefore,in this study experiments were performed on a hillslope in the Liupan Mountains,Ningxia Hui Autonomous Region,China,to quantify the unevenness of soil moisture replenishment.Soil water content(SWC)in the 0–60 cm layer and precipitation were monitored throughout the growing season in 2020 and 2021.The results showed that(1)Annual soil moisture replenishment was the highest at the mid-slope position,with an average of 309.9 mm,especially under moderate and heavy rain grade conditions,reaching 38.7% and 30.8% of the total replenishment,respectively;(2)Vertical replenishment played a dominant role in the total replenishment,accounting for 82.8%;lateral replenishment played an important but lesser role,accounting for up to 17.2% of the total replenishment;(3)Based on a soil moisture replenishment model established in this study,the maximal replenishment occurred at 90 m from the top of the slope;(4)The dominant factors contributing to the soil moisture replenishment were rainfall amount and saturated hydraulic conductivity(Ks).These findings suggest that attention should be given to both vertical and lateral soil moisture replenishment,and the mid-slope position could be preferred for site selection to achieve precise and integrated forest-water management on hillslopes in semi-arid mountainous regions. 展开更多
关键词 Soil moisture replenishment Lateral replenishment Hillslope position Loess Plateau
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Promoting China-ASEAN Digital Economy Cooperation:Progress,Challenges,and Pathways 被引量:1
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作者 Li Jia Jiang Zhida 《China International Studies》 2025年第2期69-101,共33页
Digital technology and the digital economy are at the forefront of the global technological revolution and industrial transformation.They are profoundly reshaping the international landscape of competition and restruc... Digital technology and the digital economy are at the forefront of the global technological revolution and industrial transformation.They are profoundly reshaping the international landscape of competition and restructuring the world economy.Major countries and economies around the globe are increasingly competing on digital technology and the digital economy,striving to secure a strategic advantage in the new round of international competition and establish a strong position in the evolving international order. 展开更多
关键词 digital economystriving global technological revolution secure strategic advantage establish strong position digital economy international landscape competition digital technology
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Metal-Free,Photo-Catalyzed Oxidation of Benzylic C—H Bonds to Access Carbonyl Functionality
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作者 Chen Yu-Jia Liu Zhi-Lin +2 位作者 Chen Kai Xiang Hao-Yue Yang Hua 《有机化学》 北大核心 2025年第5期1755-1762,共8页
A general metal-free photochemcial oxidation of benzylic C—H bonds has been successfully accomplished via a hydrogen atom transfer(HAT)process.A range of high value-added aromatic ketones were facilely synthesized wi... A general metal-free photochemcial oxidation of benzylic C—H bonds has been successfully accomplished via a hydrogen atom transfer(HAT)process.A range of high value-added aromatic ketones were facilely synthesized with high chemoselectivity under mild conditions.Moreover,the mild conditions by using air as the oxidant render the developed proto-col more ecofriendly and environmentally sustainable. 展开更多
关键词 PHOTOCATALYSIS hydrogen atom transfer(HAT) benzyl position oxidation
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Blind recognition of polar code parameters based on log-likelihood ratio
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作者 ZHONG Zhaogen XIE Cunxiang JIN Kun 《Journal of Systems Engineering and Electronics》 2025年第3期642-658,共17页
The syndrome a posteriori probability of the log-likelihood ratio of intercepted codewords is used to develop an algorithm that recognizes the polar code length and generator matrix of the underlying polar code.Based ... The syndrome a posteriori probability of the log-likelihood ratio of intercepted codewords is used to develop an algorithm that recognizes the polar code length and generator matrix of the underlying polar code.Based on the encoding structure,three theorems are proved,two related to the relationship between the length and rate of the polar code,and one related to the relationship between frozen-bit positions,information-bit positions,and codewords.With these three theorems,polar codes can be quickly reconstruced.In addition,to detect the dual vectors of codewords,the statistical characteristics of the log-likelihood ratio are analyzed,and then the information-and frozen-bit positions are distinguished based on the minimumerror decision criterion.The bit rate is obtained.The correctness of the theorems and effectiveness of the proposed algorithm are validated through simulations.The proposed algorithm exhibits robustness to noise and a reasonable computational complexity. 展开更多
关键词 code length frozen-bit position information-bit position log-likelihood ratio polar code
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Contralateral knee-flexion prone split-leg percutaneous nephrolithotomy:A versatile technique
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作者 Shuhang Luo Xuanfan Liu +5 位作者 Nueraili Nuermaimaiti Shuangjian Jiang Chengqiang Mo Baohua Bai Rongpei Wu Qinsong Zeng 《Asian Journal of Urology》 2025年第4期544-553,共10页
Objective:This study developed a novel technique for performing percutaneous nephrolithotomy(PCNL)in the knee-flexion prone split-leg(KF-PSL)position;this technique aimed to address the shortcomings of the traditional... Objective:This study developed a novel technique for performing percutaneous nephrolithotomy(PCNL)in the knee-flexion prone split-leg(KF-PSL)position;this technique aimed to address the shortcomings of the traditional prone(TP)position and the PSL position.The study evaluated the safety,advantages,and feasibility of the KF-PSL position compared to the TP position.Methods:A novel technique was developed based on the common PSL position.A retrospective analysis was conducted on the data of 276 patients who underwent PCNL in either the KF-PSL or TP position between January 2022 and June 2023.Demographic and perioperative clinical data of the KF-PSL and TP groups were reviewed and compared.Results:A total of 276 patients were divided into two groups based on the operative position.The preoperative parameters of the two groups did not differ significantly.The mean stone size(represented by the aggregation of the diameter of all the stones)was 40.03(SD 23.89)mm.Significant differences were found in both the mean operative time(80.9[SD 47.2]min in KF-PSL vs.107.3[SD 57.7]min in TP,p<0.001)and the stone-free rates(73% in KF-PSL vs.61% in TP,p=0.046).Braden Scale scores of the two groups did not differ significantly(p=0.12).No significant difference was observed between the groups in the total complication rate(p=0.6).Conclusion:The KF-PSL is a promising modified position for PCNL that allows for a shorter operative time,a higher stone-free rate,and a more simplified surgical procedure compared to the TP position without compromising outcomes.It is more convenient for combined therapy,allowing access to the entire urinary tract without the need for position changes. 展开更多
关键词 Percutaneous nephrolithotomy Prone split-leg position Prone position Kidney stone Retrospective study
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Leaf Position on the Sunflower Stem Determines Physiological Condition during Flowering
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作者 Antonela Markulj Kulundzic Daniela Horvat +7 位作者 Marija Kovacevic Babic Anto Mijic Aleksandra Sudaric Maja Matosa Kocar Tomislav Duvnjak Ivica Liovic Ivana Varga Marija Viljevac Vuletic 《Phyton-International Journal of Experimental Botany》 2025年第7期2075-2095,共21页
Sunflower leaf photosynthesis strongly depends on the leaf position in the plant stem conditioning,which directly affects other physiological processes.Therefore,a study of the leaf’s physiological status regarding t... Sunflower leaf photosynthesis strongly depends on the leaf position in the plant stem conditioning,which directly affects other physiological processes.Therefore,a study of the leaf’s physiological status regarding the leaf position in the stem was performed on sunflowers in the flowering stage.Eight differently positioned leaves were investigated,starting with the youngest leaf on the top of the stem to the leaves of the stem bottom,assigned as the oldest senescent leaves.According to chlorophyll fluorescence(ChlF)parameters connected to photosystem II(PSII)processes,significant changes in PSII functioning occurred only in the senescent leaves,while photosystem I(PSI)describing parameters showed a linear decrease with leaf age,i.e.,position on the stem.The antioxidative status of the leaves was dynamic,as stress indicators(lipid peroxidation and hydrogen peroxide content)fluctuated regarding leaf position on the stem,but no link was found between the activities of antioxidative enzymes and oxidative stress indicators.Linear decrease trend of secondary metabolites(mainly phenolic compounds)correlated with antioxidant activity,except for some phenolic acids(caffeic and ferulic acid),which increased in senescent leaves.The most changes in the physiological status of the leaves were confirmed in senescent leaves,which stand out the importance of younger leaves in maintaining the plant’s vitality after flowering,which is the most important for sunflower yield. 展开更多
关键词 Helianthus annuus antioxidative enzymes chlorophyll fluorescence leaf position oxidative stress PHOTOSYNTHESIS POLYPHENOLS
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Landscape Position and Shape as Drivers of Soil Properties and Quality Variation along Hillslope Sequences in a Semiarid Oak Forest
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作者 Javad Cheraghi Mehdi Heydari +3 位作者 Mahmood Rostaminia Reza Omidipour Yahya Kooch Daniel C.Dey 《Journal of Earth Science》 2025年第5期2279-2295,共17页
Forest ecosystems can be characterized by a set of catenas arranged along the slope in mountainous areas as these affect microhabitat features,which in turn influence soil properties.Heretofore,few studies have examin... Forest ecosystems can be characterized by a set of catenas arranged along the slope in mountainous areas as these affect microhabitat features,which in turn influence soil properties.Heretofore,few studies have examined how topographic variables affect soil properties and quality in semiarid regions.This study aimed to provide important insights into how catena position and shape influence soil properties,soil quality,and their interrelationships in a semiarid protected oak forest in western Iran.Basic soil properties were measured in the laboratory.In addition,the soil quality index(SQI)was calculated at different topographic positions along both convex(Λ-shaped)and concave(V-shaped)catenas at two soil depths(0-15 and 15-30 cm).The findings indicated that soil organic carbon and total nitrogen declined in the lower depth in both V-andΛ-shaped catenas and at all catena positions.The lowest porosity was observed in the lower depth at toeslope positions(TS)of both catenas.Substrate-induced respiration(SIR),microbial biomass carbon(MBC),and basal respiration(BR)were higher in the upper depths at TS positions on V-shaped catenas than onΛ-shaped catenas.These biological indices were consistently higher in the upper depths than in the lower depths across all positions of both catenas.SQI had the highest values at TS positions on both catenas and in the upper depths across all positions.Pearson correlations between soil properties indicated that SQI was most strongly and positively correlated with biological properties in both catenas.The nutrient levels,microbial activity,and soil porosity in both catena shapes and at both soil depths displayed a relatively downward trend with increasing elevation from toeslope to summit positions.The results showed that catena topographic sequence shape and position affected most of the soil properties,providing evidence of the important role of topography in creating pedodiversity in oak forest ecosystems. 展开更多
关键词 LANDFORM catena position soil depth organic carbon microbial activities environment geology
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Responses of steppe birds to habitat fragmentation:Insights from niche specialization and functional traits
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作者 Zheng Han Xi Yang +3 位作者 Lishi Zhang Piotr Tryjanowski Frédéric Jiguet Haitao Wang 《Avian Research》 2025年第3期353-361,共9页
Habitat fragmentation poses a significant threat to bird communities, especially those in open and semi-open ecosystems such as steppes. This study investigates how steppe birds adapt to and utilize fragmented habitat... Habitat fragmentation poses a significant threat to bird communities, especially those in open and semi-open ecosystems such as steppes. This study investigates how steppe birds adapt to and utilize fragmented habitats by combining niche modeling with ecological trait analysis. We conducted standardized point surveys to examine the habitat preferences of 32 bird species in Inner Mongolia, China, and quantified their habitat niche parameters using the Outlying Mean Index (OMI). Our results reveal distinct habitat preferences among species, with some thriving in intact environments while others are better adapted to fragmented areas. Grassland species showed high specialization along the fragmentation gradient, while others exhibited adaptability to varying levels of fragmentation. Using a Generalized Additive Model (GAM), we identified three key traits influencing habitat occupancy: hand-wing index, body mass, and range size. Specifically, species with medium hand-wing indices, moderate body mass, and larger range sizes were more likely to occupy heavily fragmented habitats. These findings provide empirical evidence on how habitat fragmentation affects bird species in steppe ecosystems. The study highlights the importance of functional traits in understanding avian responses to habitat fragmentation and offers a foundation for developing effective conservation strategies to preserve biodiversity in fragmented landscapes. 展开更多
关键词 CONSERVATION Functional traits Habitat fragmentation Niche position Response Steppe birds
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Numerical analysis of a vented methane/air explosion in a large-scale chamber
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作者 Huadao Xing Guangan Xu +4 位作者 Yanyu Qiu Song Sun Bin Li Mingyang Wang Lifeng Xie 《Defence Technology(防务技术)》 2025年第10期207-219,共13页
The internal and external flow fields during vented explosions of methane were characterized through numerical simulation,and the capability of numerical simulation thereof was validated by previous experimental data ... The internal and external flow fields during vented explosions of methane were characterized through numerical simulation,and the capability of numerical simulation thereof was validated by previous experimental data at three ignition positions.The venting mechanism was revealed by the simulated concentration distribution,temperature profile,and airflow velocity.The results show rear ignition results in the external methane mass distribution taking the form of"mushroom"and columnar flames in the external space,which can be expressed as a third-order polynomial relationship with distance;central ignition forms a relationship of the form y=AxB.Front ignition causes the temperature to show a tendency to repeated oscillations(rising,falling,and rising).Central ignition generates the maximum vented airflow velocity(V_(max)=320 m/s)upon vent opening.The results indicate that it is acceptable to apply numerical simulation of methane explosions in practice. 展开更多
关键词 METHANE Vented explosion Numerical simulation Ignition position Field behavior
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High Precision Sensorless Control of Rotor Mechanical Position based on Cross Correction of Dual Air Gap Information
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作者 Yukun Lin Ronggang Ni +1 位作者 Shengming Yang Qingwen Deng 《CES Transactions on Electrical Machines and Systems》 2025年第4期445-453,共9页
Position sensors are indispensable in robotic joint servo systems for acquiring mechanical positions, yet their installation inevitably occupies an axial space and increases system complexity, limiting their applicabi... Position sensors are indispensable in robotic joint servo systems for acquiring mechanical positions, yet their installation inevitably occupies an axial space and increases system complexity, limiting their applicability in compact robot design where spatial constraints and integration efficiency are critical. Sensorless control reduces mechanical and circuit complexity through hardware simplification, but inherently estimates only the electrical instead of mechanical rotor position information, thus remaining constrained in robot joint control applications. Based on the previously proposed dual-gap dualpole composite machine(DDCM), this paper systematically analyzes the causes of mechanical position estimation errors and proposes a correction method that utilizes a correction coefficient to reduce these errors and enhance estimation accuracy. Furthermore, this paper derives the applicability constraints of the proposed scheme, demonstrating that its requirements for electrical angle position errors are not stringent, thus enabling wide applicability in conventional sensorless control scenarios. The effectiveness of the proposed method is verified by conducting experiments on a 0.75 kW prototype. 展开更多
关键词 Dual-gap dual-pole composite machine(DDCM) Electrical angle position errors Mechanical position estimation errors Sensorless control
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