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Systematic analysis and modeling of the FLASH sparing effect as a function of dose and dose rate
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作者 Qi-Bin Fu Yan Zhang +3 位作者 Yu-Cheng Wang Tu-Chen Huang Hong-Yu Zhu Xiao-Wu Deng 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2024年第10期51-58,共8页
Ultrahigh-dose-rate radiotherapy(FLASH-RT)is a revolutionary radiotherapy technology that can spare normal tissues without compromising tumor control.Although qualitative experimental results have been reported,quanti... Ultrahigh-dose-rate radiotherapy(FLASH-RT)is a revolutionary radiotherapy technology that can spare normal tissues without compromising tumor control.Although qualitative experimental results have been reported,quantitative and systematic analysis of data is necessary.Particularly,the FLASH effect response model to the dose or dose rate is still unclear.This study investigated the relationships between the FLASH effect and experimental parameters,such as dose,dose rate,and other factors by analyzing published in vivo experimental data from animal models.The data were modeled based on logistic regression analysis using the sigmoid function.The model was evaluated using prediction accuracy,receiver operating characteristic(ROC)curve,and area under the ROC curve.Results showed that the FLASH effect was closely related to the dose,mean dose rate,tissue type,and corresponding biological endpoints.The dose rate corresponding to a 50% probability of triggering cognitive protection in the brain was 45 Gy s^(-1).The dose rate corresponding to a 50% probability of triggering intestinal crypt survival and regeneration was 140 Gy s^(-1).For the skin toxicity effect,the dose corresponding to a 50% probability of triggering the FLASH effect was 24 Gy.This study helps to characterize the conditions underlying the FLASH effect and provides important information for optimizing experiments. 展开更多
关键词 FLASH radiotherapy Sparing effect Systematic analysis Dose rate DOSE Biological endpoints
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Decoupling of temporal/spatial broadening effects in Doppler wind LiDAR by 2D spectral analysis
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作者 刘珍 张云鹏 +3 位作者 竹孝鹏 刘继桥 毕德仓 陈卫标 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第3期447-452,共6页
Pulse echo accumulation is commonly employed in coherent Doppler wind LiDAR(light detection and ranging)under the assumption of steady wind.Here,the measured spectral data are analyzed in the time dimension and freque... Pulse echo accumulation is commonly employed in coherent Doppler wind LiDAR(light detection and ranging)under the assumption of steady wind.Here,the measured spectral data are analyzed in the time dimension and frequency dimension to cope with the temporal wind shear and achieve the optimal accumulation time.A hardware-efficient algorithm combining the interpolation and cross-correlation is used to enhance the wind retrieval accuracy by reducing the frequency sampling interval and then reduce the spectral width calculation error.Moreover,the temporal broadening effect and spatial broadening effect are decoupled according to the strategy we developed. 展开更多
关键词 Doppler wind LiDAR spectral analysis hardware efficiency spectrum broadening effects
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Effect of boundary conditions on shakedown analysis of heterogeneous materials
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作者 Xiuchen GONG Yinghao NIE +1 位作者 Gengdong CHENG Kai LI 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2024年第1期39-68,共30页
The determination of the ultimate load-bearing capacity of structures made of elastoplastic heterogeneous materials under varying loads is of great importance for engineering analysis and design. Therefore, it is nece... The determination of the ultimate load-bearing capacity of structures made of elastoplastic heterogeneous materials under varying loads is of great importance for engineering analysis and design. Therefore, it is necessary to accurately predict the shakedown domains of these materials. The static shakedown theorem, also known as Melan's theorem, is a fundamental method used to predict the shakedown domains of structures and materials. Within this method, a key aspect lies in the construction and application of an appropriate self-equilibrium stress field(SSF). In the structural shakedown analysis, the SSF is typically constructed by governing equations that satisfy no external force(NEF) boundary conditions. However, we discover that directly applying these governing equations is not suitable for the shakedown analysis of heterogeneous materials. Researchers must consider the requirements imposed by the Hill-Mandel condition for boundary conditions and the physical significance of representative volume elements(RVEs). This paper addresses this issue and demonstrates that the sizes of SSFs vary under different boundary conditions, such as uniform displacement boundary conditions(DBCs), uniform traction boundary conditions(TBCs), and periodic boundary conditions(PBCs). As a result, significant discrepancies arise in the predicted shakedown domain sizes of heterogeneous materials. Built on the demonstrated relationship between SSFs under different boundary conditions, this study explores the conservative relationships among different shakedown domains, and provides proof of the relationship between the elastic limit(EL) factors and the shakedown loading factors under the loading domain of two load vertices. By utilizing numerical examples, we highlight the conservatism present in certain results reported in the existing literature. Among the investigated boundary conditions, the obtained shakedown domain is the most conservative under TBCs.Conversely, utilizing PBCs to construct an SSF for the shakedown analysis leads to less conservative lower bounds, indicating that PBCs should be employed as the preferred boundary conditions for the shakedown analysis of heterogeneous materials. 展开更多
关键词 heterogeneous material self-equilibrium stress field(SSF) shakedown analysis effect of boundary conditions
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Intraoperative thermostatic nursing and failure mode and effects analysis enhance gastrectomies’ care quality
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作者 Xian-Yong Wang Yi-Lei Zhao +3 位作者 Sha-Sha Wen Xiao-Yu Song Lu Mo Zhi-Wei Xiao 《World Journal of Gastrointestinal Surgery》 SCIE 2024年第12期3764-3771,共8页
BACKGROUND Utilizing failure mode and effects analysis(FMEA)in operating room nursing provides valuable insights for the care of patients undergoing radical gastric cancer surgery.AIM To evaluate the impact of FMEA on... BACKGROUND Utilizing failure mode and effects analysis(FMEA)in operating room nursing provides valuable insights for the care of patients undergoing radical gastric cancer surgery.AIM To evaluate the impact of FMEA on the risk of adverse events and nursing-care quality in patients undergoing radical surgery.METHODS Among 230 patients receiving radical cancer surgery between May 2019 and May 2024,115 were assigned to a control group that received standard intraoperative thermoregulation,while the observation group benefited from FMEA-modeled operating room care.Clinical indicators,stress responses,postoperative gastroin-testinal function recovery,nursing quality,and the incidence of adverse events were compared between the two groups.RESULTS Significant differences were observed in bed and hospital stay durations between the groups(P<0.05).There were no significant differences in intraoperative blood loss or postoperative body temperature(P>0.05).Stress scores improved in both groups post-nursing(P<0.05),with the observation group showing lower stress scores than the control group(P<0.05).Gastrointestinal function recovery and nursing quality scores also differed significantly(P<0.05).Additionally,the incidence of adverse events such as stress injuries and surgical infections varied notably between the groups(P<0.05).CONCLUSION Incorporating FMEA into operating room nursing significantly enhances patient care by improving safety,expediting recovery,and reducing healthcare-associated risks. 展开更多
关键词 Constant temperature nursing Failure mode and effects analysis model Operating room nursing Radical gastric cancer Nursing quality
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A Study of the Teaching Effects of Case Analysis in Cross-Cultural Communication Class-Taking Individualism-Collectivism Cultural Dimension Class as an Example
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作者 ZHOU Qingyan 《Sino-US English Teaching》 2024年第8期372-376,共5页
This study introduces the individualism-collectivism dimension of the cultural dimension of cross-cultural communication initiated by Geert Hofstede.Different cultures must develop a way of correlating that strikes a ... This study introduces the individualism-collectivism dimension of the cultural dimension of cross-cultural communication initiated by Geert Hofstede.Different cultures must develop a way of correlating that strikes a balance between caring for themselves and showing concern for others.Individualist culture encourages uniqueness and independence while collectivist culture emphasizes conformity and mutual assistance.This article introduces how to use case analysis method to effectively carry out classroom teaching in this cultural dimension. 展开更多
关键词 cultural dimension case analysis cross cultural communication teaching effects
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Geospatial Analysis of Urban Heat Island Effects and Tree Equity
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作者 Jillian Gorrell Sharon R. Jean-Philippe +3 位作者 Paul D. Ries Jennifer K. Richards Neelam C. Poudyal Rochelle Butler 《Open Journal of Forestry》 2024年第1期1-18,共18页
In recent decades, Urban Heat Island Effects have become more pronounced and more widely examined. Despite great technological advances, our current societies still experience great spatial disparity in urban forest a... In recent decades, Urban Heat Island Effects have become more pronounced and more widely examined. Despite great technological advances, our current societies still experience great spatial disparity in urban forest access. Urban Heat Island Effects are measurable phenomenon that are being experienced by the world’s most urbanized areas, including increased summer high temperatures and lower evapotranspiration from having impervious surfaces instead of vegetation and trees. Tree canopy cover is our natural mitigation tool that absorbs sunlight for photosynthesis, protects humans from incoming radiation, and releases cooling moisture into the air. Unfortunately, urban areas typically have low levels of vegetation. Vulnerable urban communities are lower-income areas of inner cities with less access to heat protection like air conditioners. This study uses mean evapotranspiration levels to assess the variability of urban heat island effects across the state of Tennessee. Results show that increased developed land surface cover in Tennessee creates measurable changes in atmospheric evapotranspiration. As a result, the mean evapotranspiration levels in areas with less tree vegetation are significantly lower than the surrounding forested areas. Central areas of urban cities in Tennessee had lower mean evapotranspiration recordings than surrounding areas with less development. This work demonstrates the need for increased tree canopy coverage. 展开更多
关键词 Spatial analysis Land Cover Urban Heat Island effect (UHIE) EVAPOTRANSPIRATION Tree Canopy Impervious Surface GIS Prediction Model GIS Machine Learning
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Analysis of the Effect of Humanistic Care in the Process of Pre-Hospital Emergency Care
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作者 Rui Cao Zhe Chen 《Journal of Clinical and Nursing Research》 2024年第8期302-305,共4页
Objective:To explore the effectiveness of humanistic care in pre-hospital emergency care.Methods:From April 2020 to January 2021,80 pre-hospital emergency patients were studied.The patients were randomly divided into ... Objective:To explore the effectiveness of humanistic care in pre-hospital emergency care.Methods:From April 2020 to January 2021,80 pre-hospital emergency patients were studied.The patients were randomly divided into two groups:a control group(n=40),which received conventional care,and an experimental group(n=40),which received humanistic care.The effects of nursing care and psychological state were compared between the two groups.Results:The experimental group showed better nursing outcomes and a more positive psychological state compared to the control group(P<0.05).Conclusion:Humanistic care in pre-hospital emergency settings is more effective in reducing patients’anxiety and depression,enhancing the operational abilities and service attitudes of nursing staff,and increasing the emergency success rate. 展开更多
关键词 Humanistic care Pre-hospital emergency care Negative emotion effect analysis
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Evaluating and Improving the Effectiveness of Vehicle Inspection and Maintenance Programs: A Cost-Benefit Analysis Framework
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作者 Ying Li 《Journal of Environmental Protection》 2017年第12期1541-1566,共26页
Motor vehicle inspection and maintenance (I/M) programs are designed to identify high-emitting vehicles and mitigate their impacts on air quality and climate. I/M programs have been traditionally ranked superior among... Motor vehicle inspection and maintenance (I/M) programs are designed to identify high-emitting vehicles and mitigate their impacts on air quality and climate. I/M programs have been traditionally ranked superior among various vehicle emission control measures by the results of cost-benefit analysis, based on the assumption that these programs will achieve the targeted emission reduction outcomes. However, the actual effects of I/M programs may be greatly uncertain and when this uncertainty is taken into account, these programs may become suboptimal. This study develops a new a cost-benefit analysis framework that links various program design consideration, such as program participation rate, identification rate and effective repair rate, to the public health benefits as well as costs of the programs. This framework helps decision makers to investigate minimum implementation requirements that at least ensure the benefits are greater than the costs of implementing the programs in order to improve the overall effectiveness of the I/M programs. To illustrate the applications of the framework, it was applied to a particulate matter oriented I/M program targeting all diesel-fueled vehicles in the city of Bangkok, Thailand, a large metropolitan area that has been suffering from severe ambient PM pollution mainly attributable to its wide use of diesel-fueled vehicles and motorcycles. It was found that the health benefits achieved from the program are sensitive to several key program design elements, including participation rate and problem vehicle identification rate, fraction of effective repairs and illegal operation rate. Other variables, such as the testing cut-points and vehicle population growth rate, only have modest effects on the overall emission reduction and consequent health benefits. Overall, the performance of multiple variables associated with I/M program design needs to be improved simultaneous in order to achieve the targeted benefits of the program. 展开更多
关键词 INSPECTION and Maintenance PROGRAMS cost-BENEFIT analysis effectIVENESS PROGRAM Design
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High-resolution microendoscopy for esophageal cancer screening in China: A cost-effectiveness analysis 被引量:9
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作者 Chin Hur Sung Eun Choi +8 位作者 Chung Yin Kong Gui-Qi Wang Hong Xu Alexandros D Polydorides Li-Yan Xue Katherine E Perzan Angela C Tramontano Rebecca R Richards-Kortum Sharmila Anandasabapathy 《World Journal of Gastroenterology》 SCIE CAS 2015年第18期5513-5523,共11页
AIM:To study the cost-effectiveness of high-resolution microendoscopy(HRME)in an esophageal squamous cell carcinoma(ESCC)screening program in China.METHODS:A decision analytic Markov model of ESCC was developed.Separa... AIM:To study the cost-effectiveness of high-resolution microendoscopy(HRME)in an esophageal squamous cell carcinoma(ESCC)screening program in China.METHODS:A decision analytic Markov model of ESCC was developed.Separate model analyses were conducted for cohorts consisting of an averagerisk population or a high-risk population in China.Hypothetical 50-year-old individuals were followed until age 80 or death.We compared three different strategies for both cohorts:(1)no screening;(2)standard endoscopic screening with Lugol’s iodine staining;and(3)endoscopic screening with Lugol’s iodine staining and an HRME.Model parameters were estimated from the literature as well as from GLOBOCAN,the Cancer Incidence and Mortality Worldwide cancer database.Health states in the model included non-neoplasia,mild dysplasia,moderate dysplasia,high-grade dysplasia,intramucosal carcinoma,operable cancer,inoperable cancer,and death.Separate ESCC incidence transition rates were generated for the average-risk and high-risk populations.Costs in Chinese currency were converted to international dollars(I$)and were adjusted to 2012dollars using the Consumer Price Index.RESULTS:The main outcome measurements for this study were quality-adjusted life years(QALYs)and incremental cost-effectiveness ratio(ICER).For the average-risk population,the HRME screening strategy produced 0.043 more QALYs than the no screening strategy at an additional cost of I$646,resulting in an ICER of I$11808 per QALY gained.Standard endoscopic screening was weakly dominated.Among the high-risk population,when the HRME screening strategy was compared with the standard screening strategy,the ICER was I$8173 per QALY.For both the high-risk and average-risk screening populations,the HRME screening strategy appeared to be the most cost-effective strategy,producing ICERs below the willingness-topay threshold,I$23500 per QALY.One-way sensitivity analysis showed that,for the average-risk population,higher specificity of Lugol’s iodine(>40%)and lower specificity of HRME(<70%)could make Lugol’s iodine screening cost-effective.For the high-risk population,the results of the model were not substantially affected by varying the follow-up rate after Lugol’s iodine screening,Lugol’s iodine test characteristics(sensitivity and specificity),or HRME specificity.CONCLUSION:The incorporation of HRME into an ESCC screening program could be cost-effective in China.Larger studies of HRME performance are needed to confirm these findings. 展开更多
关键词 cost-effectIVENESS analysis Diagnostic imaging ENDOSCOPY ESOPHAGEAL SQUAMOUS cell cancer Simulation disease model
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Cost-Effectiveness Analysis of Oral Hypoglycemics for Type-2 Diabetes Mellitus at a Tertiary Care Hospital, Nepal
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作者 Saroj Dhakal Shrijana Shakya Shree Krishna Sharma 《Journal of Pharmacy and Pharmacology》 2019年第10期546-556,共11页
An observational follow-up study on 63 newly diagnosed Type-Ⅱ diabetic patients was conducted at Tribhuvan University Teaching Hospital, a tertiary care centre, Kathmandu, Nepal. The aims of the study were to determi... An observational follow-up study on 63 newly diagnosed Type-Ⅱ diabetic patients was conducted at Tribhuvan University Teaching Hospital, a tertiary care centre, Kathmandu, Nepal. The aims of the study were to determine demographics, prescribing patterns, drug costs and to analyze the effectiveness of different hypoglycemic therapies. The effectiveness of glucose control was analyzed by Wilcoxon signed rank test. The majority of patients (31%) fell into the age strata of 50-60 years. A total of 63 prescriptions were screened including anti-diabetics drugs and other drugs. The average number of drugs per prescription sheet was 2.72 ± 2.23. Eighty-two percent (82%) of the patients were recommended oral hypoglycemic agents. The prescribing frequency of biguanides was more than sulphonylureas. Biguanides were prescribed more frequently than sulfonylureas. The biguanide monotherapy group (p = 0.001) and the combination of biguanide and sulfonylureas (p = 0.028) were the most effective treatment methods, and the p-value of fasting blood glucose was the lowest at follow-up. Nearly 55% of patients receiving the combination achieved glucose control. In summary, this study reflects the best treatment for patients with diabetes. Future studies of larger patient populations need to evaluate existing treatment models to ensure good practice and quality of care. 展开更多
关键词 DIABETES milltus cost effectiveness analysis BIGUANIDES SULPHONYLUREAS HBA1C Nepal
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Molecular Tagging and Effect Analysis of a New Small Grain Dwarf Gene in Rice 被引量:4
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作者 李秀兰 吴成 +3 位作者 邓晓建 王平荣 李仁端 杨志荣 《Acta Botanica Sinica》 CSCD 2003年第7期757-761,共5页
Plant height is one of the important agronomic traits of rice. Over higher plant would easily result in plant lodging and output reducing. On the other hand, the dwarf varieties with proper plant height had higher lod... Plant height is one of the important agronomic traits of rice. Over higher plant would easily result in plant lodging and output reducing. On the other hand, the dwarf varieties with proper plant height had higher lodging resistance and a greater harvest index, allowing for the increased use of nitrogen fertilizer. Dwarf breeding had made a great breakthrough in the rice breeding. The breeding and extension of excellent dwarf varieties remarkably improved the yield potential of rice. Therefore, the plant height is still one of the focuses in rice genetic research. 展开更多
关键词 Oryza sativa dwarf gene gene mapping microsatellite marker gene effect analysis
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Analysis of stability and bullwhip effect in production-inventory systems 被引量:5
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作者 张冲 王海燕 《Journal of Southeast University(English Edition)》 EI CAS 2011年第1期101-106,共6页
To discuss the relationship between stability and bullwhip effect in the supply chain system,a basic model in a production-inventory control system is developed using difference equations.Z-transform techniques are ap... To discuss the relationship between stability and bullwhip effect in the supply chain system,a basic model in a production-inventory control system is developed using difference equations.Z-transform techniques are applied to investigate the production ordering and inventory dynamics.For the two operational regimes of sufficient inventory coverage and insufficient inventory coverage,the scope of decision parameters which make the system stable or instable is investigated.Under two operational regimes and the actual system,production release rates,stability/instability and bullwhip effect in the stable region and instable region are examined based on different demand functions,and then the numerical simulation results are given.The results show that reasonable choices of fractional adjustment of inventory and supply line can make the system stable and decrease bullwhip effect.It is summarized that the piecewise linearization based on the stability analysis approach is a valid approximation to the analysis of production-inventory ordering systems with nonlinearities.Some interesting results are obtained and they have important implications for improving inventory and order decisions in supply chain systems. 展开更多
关键词 production-inventory systems stability analysis bullwhip effect Z-TRANSFORM
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Improved Statistical Interconnect Timing Analysis Considering Scattering Effect
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作者 林赛华 杨华中 +1 位作者 罗嵘 汪蕙 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2006年第11期1918-1922,共5页
We propose an improved statistical approach for modeling interconnect slew that takes into account the scattering effect of a nanoscale wire. We first propose a simple, closed-form scattering effect resistivity model,... We propose an improved statistical approach for modeling interconnect slew that takes into account the scattering effect of a nanoscale wire. We first propose a simple, closed-form scattering effect resistivity model, considering the effects of both width and thickness. Then we use this model to derive statistical expressions of the slew metrics using the SS2M model. We find that the delay and slew can be greatly increased when considering the scattering effect. The proposed statistical SS2M model has an average error of 4.16% with respect to SPICE Monte Carlo simulations, with an average error of standard deviation of only 3.06%. 展开更多
关键词 INTERCONNECT scatterin effect timin analysis
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Cost-Effectiveness Analysis of Atezolizumab plus Pemetrexed and Platinum in First-Line Treatment of Non-Squamous Non-Small Cell Lung Cancer in China
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作者 Wenyue Wang Yongfa Chen 《Pharmacology & Pharmacy》 2022年第6期164-173,共10页
Objective: To evaluate the cost-effectiveness of atezolizumab plus pemetrexed and platinum-based (APP) in the first-line treatment of non-squamous non- small cell lung cancer (NSCLC). Methods: A partitioned survival m... Objective: To evaluate the cost-effectiveness of atezolizumab plus pemetrexed and platinum-based (APP) in the first-line treatment of non-squamous non- small cell lung cancer (NSCLC). Methods: A partitioned survival model (PSM) was constructed based on the IMpower132 clinical trial. Total cost, quality- adjusted life years (QALY), and incremental cost-effectiveness ratio (ICER) were the main outputs of the model. Deterministic sensitivity analysis and probabilistic sensitivity analysis were adopted to test the uncertainty of the parameters. Results: The results of the base-case analysis illustrated that compared with PP, the incremental cost of APP was CNY 591040.94, the incremental utility was 0.46 QALY, and the ICER was CNY 1291414.83/QALY. Deterministic sensitivity analysis results illustrated that atezolizumab and other parameters have a greater impact on ICER. Probabilistic sensitivity analysis results show that no matter how each parameter changes, under the willingness to pay threshold of 3-times Chinese per capita GDP, the probability of APP has cost-effectiveness is 0. Conclusion: From the perspective of the Chinese health system, APP is not cost-effective for first-line treatment of non-squamous non-small cell lung cancer without sensitizing EGFR or ALK genetic alterations. 展开更多
关键词 Atezolizumab Non-Small Cell Lung Cancer Partitioned Survival Model cost-effectiveness analysis
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Causal Analysis Between Rice Growth and Cadmium Accumulation and Transfer under Arbuscular Mycorrhizal Inoculation 被引量:2
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作者 ZHAO Ting WANG Li +1 位作者 YANG Jixian MA Fang 《Rice science》 SCIE CSCD 2024年第2期226-236,共11页
Cadmium(Cd)contamination in rice has been a serious threat to human health.To investigate the effects of arbuscular mycorrhizal fungi(AMF)on the Cd translocation in rice,a controlled pot experiment was conducted.The r... Cadmium(Cd)contamination in rice has been a serious threat to human health.To investigate the effects of arbuscular mycorrhizal fungi(AMF)on the Cd translocation in rice,a controlled pot experiment was conducted.The results indicated that AMF significantly increased rice biomass,with an increase of up to 40.0%,particularly in root biomass by up to 68.4%.Notably,the number of prominent rice individuals also increased,and their plasticity was enhanced following AMF inoculation.AMF led to an increase in the net photosynthetic rate and antioxidant enzyme activity of rice.In the AMF treatment group,the Cd concentration in the rice roots was significantly higher(19.1%‒68.0%)compared with that in the control group.Conversely,the Cd concentration in the rice seeds was lower in the AMF treatment group,indicating that AMF facilitated the sequestration of Cd in rice roots and reduced Cd accumulation in the seeds.Path coefficients varied across different treatments,suggesting that AMF inoculation reduced the direct impact of soil Cd concentration on the total Cd accumulation in seeds.The translocation of Cd was consistently associated with simultaneous growth dilution and compensatory accumulation as a result of mycorrhizal effects.Our study quantitatively analyzed this process through path analysis and clarified the causal relationship between rice growth and Cd transfer under the influence of AMF. 展开更多
关键词 cadmium transfer dilution effect heavy metal immobilization mycorrhizal effect path analysis phenotypic plasticity
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Analysis on the Application of Schema Theory to Improve English Listening Teaching Effectiveness 被引量:1
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作者 黄莹 《海外英语》 2013年第4X期17-18,21,共3页
Based on the schema theory,the paper analyzes the psychological cognitive process of listening comprehension.Schema theory provides a good theoretical basis to improve the English listening teaching effectiveness.Prac... Based on the schema theory,the paper analyzes the psychological cognitive process of listening comprehension.Schema theory provides a good theoretical basis to improve the English listening teaching effectiveness.Practice shows that the schema theory application to guide teaching practice can achieve great progress in an English listening classroom. 展开更多
关键词 SCHEMA theory LISTENING COMPREHENSION COGNITIVE an
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Semi-analytical solution for drained expansion analysis of a hollow cylinder of critical state soils 被引量:1
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作者 He Yang Jialiang Zhang +1 位作者 Haisui Yu Peizhi Zhuang 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第6期2326-2340,共15页
The expansion of a thick-walled hollow cylinder in soil is of non-self-similar nature that the stress/deformation paths are not the same for different soil material points.As a result,this problem cannot be solved by ... The expansion of a thick-walled hollow cylinder in soil is of non-self-similar nature that the stress/deformation paths are not the same for different soil material points.As a result,this problem cannot be solved by the common self-similar-based similarity techniques.This paper proposes a novel,exact solution for rigorous drained expansion analysis of a hollow cylinder of critical state soils.Considering stress-dependent elastic moduli of soils,new analytical stress and displacement solutions for the nonself-similar problem are developed taking the small strain assumption in the elastic zone.In the plastic zone,the cavity expansion response is formulated into a set of first-order partial differential equations(PDEs)with the combination use of Eulerian and Lagrangian descriptions,and a novel solution algorithm is developed to efficiently solve this complex boundary value problem.The solution is presented in a general form and thus can be useful for a wide range of soils.With the new solution,the non-self-similar nature induced by the finite outer boundary is clearly demonstrated and highlighted,which is found to be greatly different to the behaviour of cavity expansion in infinite soil mass.The present solution may serve as a benchmark for verifying the performance of advanced numerical techniques with critical state soil models and be used to capture the finite boundary effect for pressuremeter tests in small-sized calibration chambers. 展开更多
关键词 Cavity expansion Drained analysis Boundary effect Critical state soil Non-self-similar Eulerian-Lagrangian approach
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Study on effectiveness evaluation of weapon systems based on grey relational analysis and TOPSIS 被引量:54
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作者 Gu Hui Song Bifeng 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2009年第1期106-111,共6页
To evaluate the effectiveness of weapon systems, the advantages and disadvantages of grey relational analysis and TOPSIS for multiattribute decision-making is pointed out, and an effectiveness evaluation model of weap... To evaluate the effectiveness of weapon systems, the advantages and disadvantages of grey relational analysis and TOPSIS for multiattribute decision-making is pointed out, and an effectiveness evaluation model of weapon systems by combining grey relational analysis and TOPSIS is proposed. The model aggregates the grey relational grade and the distance to a new integrated closeness and reflects not only the trend but also the situation of the alternative. The example illuminates that the model is effective for the effectiveness evaluation of weapon systems. 展开更多
关键词 multiattribute decision-making effectiveness evaluation grey relational analysis TOPSIS integratedcloseness.
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Numerical Analysis of a Spiral-groove Dry-gas Seal Considering Micro-scale Effects 被引量:12
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作者 WANG Bing ZHANG Huiqiang 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2011年第1期146-153,共8页
A dry-gas seal system is a non-contact seal technology that is widely used in different industrial applications.Spiral-groove dry-gas seal utilizes fluid dynamic pressure effects to realize the seal and lubrication pr... A dry-gas seal system is a non-contact seal technology that is widely used in different industrial applications.Spiral-groove dry-gas seal utilizes fluid dynamic pressure effects to realize the seal and lubrication processes,while forming a high pressure gas film between two sealing faces due to the deceleration of the gas pumped in or out.There is little research into the effects and the influence on seal performance,if the grooves and the gas film are at the micro-scale.This paper investigates the micro-scale effects on spiral-groove dry-gas seal performance in a numerical solution of a corrected Reynolds equation.The Reynolds equation is discretized by means of the finite difference method with the second order scheme and solved by the successive-over-relaxation(SOR) iterative method.The Knudsen number of the flow in the sealing gas film is changed from 0.005 to 0.120 with a variation of film depth and sealing pressure.The numerical results show that the average pressure in the gas film and the sealed gas leakage increase due to micro-scale effects.The open force is enlarged,while the gas film stiffness is significantly decreased due to micro-scale effects.The friction torque and power consumption remain constant,even in low sealing pressure and spin speed conditions.In this paper,the seal performance at different rotor face spin speeds is also described.The proposed research clarifies the micro-scale effects in a spiral-groove dry-gas seal and their influence on seal performance,which is expected to be useful for the improvement of the design of dry-gas seal systems operating in the slip flow regime. 展开更多
关键词 micro-scale effect spiral-groove dry-gas seal numerical analysis Reynolds equation
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Soil Plug Effect Prediction and Pile Driveability Analysis for Large-Diameter Steel Piles in Ocean Engineering 被引量:16
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作者 刘润 闫澍旺 李志华 《China Ocean Engineering》 SCIE EI 2009年第1期107-118,共12页
Long steel piles with large diameters have been more widely used in the field of ocean engineering. Owing to the pile with a large diameter, soil plug development during pile driving has great influences on pile drive... Long steel piles with large diameters have been more widely used in the field of ocean engineering. Owing to the pile with a large diameter, soil plug development during pile driving has great influences on pile driveability and bearing capacity. The response of soil plug developed inside the open-ended pipe pile during the dynamic condition of pile-driving is different from the response under the static condition of loading during service. This paper addresses the former aspect. A numerical procedure for soil plug effect prediction and pile driveabihty analysis is proposed and described. By taking into consideration of the pile dimension effect on side and tip resistance, this approach introduces a dimensional coefficient to the conventional static eqnihbrium equations for the plug differential unit and proposes an improved static equity method for the plug effect prediction. At the same time, this approach introduces a simplified model by use of one-dimensional stress wave equation to simulate the interaction between soil plug and pile inner wall. The proposed approach has been applied in practical engineering analyses. Results show that the calculated plug effect and pile driveabihty based on the proposed approach agree well with the observed data. 展开更多
关键词 large diameter steel piles soil plug plug effect static equity method interaction between the plug and pile inner wall driveability analysis
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