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A review of the methods for determining cost-effectiveness threshold in health care 被引量:1
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作者 宗欣 孙利华 《Journal of Chinese Pharmaceutical Sciences》 CAS 2011年第6期542-548,共7页
Cost-effectiveness analysis(CEA) is increasingly important in health care decision making.Cost-effectiveness threshold is a critical parameter in the cost-effectiveness analysis.This review introduces the concept of... Cost-effectiveness analysis(CEA) is increasingly important in health care decision making.Cost-effectiveness threshold is a critical parameter in the cost-effectiveness analysis.This review introduces the concept of cost-effectiveness threshold, summarizes its determining methods,and classifies the existing methods into two kinds according to budget constraints,then analyzes the merit and demerit of every methods.When there is a flexible budget,the methods for determining the cost-effectiveness threshold include inferring the threshold from previous decisions,comparison with other health care technology or transfer from elsewhere in the public sector,social willingness-to-pay approach,GDP per capita criteria,and rule of thumb.When there is a fixed budget,the methods for determining the cost-effectiveness threshold include shadow price approach,opportunity cost approach,and ICER threshold-searcher model.Each approach to determining threshold has its strength and weakness.The aim of this article is to introduce the existing methods and discuss the features of each method.The background information,such as the definition of threshold,is also described.The basic theory of cost-effectiveness threshold is elaborated,and we recommend the establishment of a cost-effectiveness threshold in the Chinese health care. 展开更多
关键词 cost-effectiveness threshold Determining methods Budget constraints Resource allocation
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Cost-Effectiveness Analysis of Combined Chemotherapy Regimen Containing Bedaquiline in the Treatment of Multidrug-Resistant Tuberculosis in China 被引量:1
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作者 XU Cai Hong QIU Ying Peng +5 位作者 HE Zi Long HU Dong Mei YUE Xiao CHEN Zhong Dan XU Yuan Yuan ZHAO Yan Lin 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 2023年第6期501-509,共9页
Objective This study aims to estimate the cost-effectiveness of the combined chemotherapy regimen containing Bedaquiline(BR)and the conventional treatment regimen(CR,not containing Bedaquiline)for the treatment of adu... Objective This study aims to estimate the cost-effectiveness of the combined chemotherapy regimen containing Bedaquiline(BR)and the conventional treatment regimen(CR,not containing Bedaquiline)for the treatment of adults with multidrug-resistant tuberculosis(MDR-TB)in China.Methods A combination of a decision tree and a Markov model was developed to estimate the cost and effects of MDR patients in BR and CR within ten years.The model parameter data were synthesized from the literature,the national TB surveillance information system,and consultation with experts.The incremental cost-effectiveness ratio(ICER)of BR vs.CR was determined.Results BR(vs.CR)had a higher sputum culture conversion rate and cure rate and prevented many premature deaths(decreased by 12.8%),thereby obtaining more quality-adjusted life years(QALYs)(increased by 2.31 years).The per capita cost in BR was as high as 138,000 yuan,roughly double that of CR.The ICER for BR was 33,700 yuan/QALY,which was lower than China's 1×per capita Gross Domestic Product(GDP)in 2020(72,400 yuan).Conclusion BR is shown to be cost effective.When the unit price of Bedaquiline reaches or falls below57.21 yuan per unit,BR is expected to be the dominant strategy in China over CR. 展开更多
关键词 Bedaquiline cost-effectiveness Multidrug-resistant tuberculosis China
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Cost-effectiveness of robotic-assisted spinal surgery:A single-center retrospective study
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作者 Sorayouth Chumnanvej Krish Ariyaprakai +3 位作者 Branesh M.Pillai Jackrit Suthakorn Sharvesh Gurusamy Siriluk Chumnanvej 《Laparoscopic, Endoscopic and Robotic Surgery》 2023年第4期147-153,共7页
Objective:Robotic-assisted spine surgeries(RASS)have been shown to enhance precision,reduce operative time,prevent complications,facilitate minimally invasive spinal surgery,and decrease revision surgery rates,leading... Objective:Robotic-assisted spine surgeries(RASS)have been shown to enhance precision,reduce operative time,prevent complications,facilitate minimally invasive spinal surgery,and decrease revision surgery rates,leading to improved patient outco mes This study aimed to compare the cost-effectiveness of RAs's and non-robotic-assisted surgery for degenerative spine disease at a single center.Me thods:This retrospective study,including 122 patients,was conducted at a single center from March 2015 to February 2022.Patients who underwent ro bot-assisted surgery were assigned to the robotgroup,and patients who underwent non-robotic-assisted surgery were assigned to the non-mmbot group.Various data,indluding demographic information,surgical details,outcomes,and cost-effectiveness,were colected for both groups.The cost-effectiveness was determined using the incremental cost-effectiveness ratio(ICER),and subgroup analysis was conducted for patients with 1 or 2 levels of spi-nal instrumentation.The analysis was performed using STATA SE version 15 and Tree.Age Pro 2020,with Monte Caro simulations for the cost-effectiveness acceptability curve.Results The owerallICER was$22,572,but it decreased to$16,980 when considering cases with only 1or 2 levels of instrumentation.RASS is deemed cost-effective when the willi ingness to pay is$3000-$4000 if less than 2 levels of the spine are instrumented.Conchsions:The cost-effectiveness of robot icassistance be comes apparent whenthere isa reduced need for open surgeries,leading to decreased d revision rates caused by complications such as misplaced screwsor infctions.Therefore,it is advisable to allocate healthcare budget resou Irces to spine robots,as RASS PIDves to be cost-effective,partic cularly when only two or Ewer spinal levels require instrumentation. 展开更多
关键词 Robotic Spine surgery Incremental cost-effectiveness ratio cost-effectiveness acceptability curve Levels of spine fixation
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Cost-effectiveness of patient specific vs conventional instrumentation for total knee arthroplasty:A systematic review and meta-analysis
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作者 Isobel M Dorling Lars Geenen +3 位作者 Marion J L F Heymans Jasper Most Bert Boonen Martijn G M Schotanus 《World Journal of Orthopedics》 2023年第6期458-470,共13页
BACKGROUND Over the past years,patient specific instrumentation(PSI)for total knee arthroplasty(TKA)has been implemented and routinely used.No clear answer has been given on its associated cost and cost-effectiveness ... BACKGROUND Over the past years,patient specific instrumentation(PSI)for total knee arthroplasty(TKA)has been implemented and routinely used.No clear answer has been given on its associated cost and cost-effectiveness when compared to conventional instrumentation(CI)for TKA.AIM To compare the cost and cost-effectiveness of PSI TKA compared to CI TKA.METHODS A literature search was performed in healthcare,economical healthcare,and medical databases(MEDLINE,EMBASE,CINAHL,Web of Science,Cochrane Library,EconLit).It was conducted in April 2021 and again in January 2022.Relevant literature included randomised controlled trials,retrospective studies,prospective studies,observational studies,and case control studies.All studies were assessed on methodological quality.Relevant outcomes included incremental cost-effectiveness ratio,quality-adjusted life years,total costs,imaging costs,production costs,sterilization associated costs,surgery duration costs and readmission rate costs.All eligible studies were assessed for risk of bias.Meta-analysis was performed for outcomes with sufficient data.RESULTS Thirty-two studies were included into the systematic review.Two were included in the metaanalysis.3994 PSI TKAs and 13267 CI TKAs were included in the sample size.The methodological quality of the included studies,based on Consensus on Health Economic Criteria-scores and risk of bias,ranged from average to good.PSI TKA costs less than CI TKA when considering mean operating room time and its associated costs and tray sterilization per patient case.PSI TKA costs more compared to CI TKA when considering imaging and production costs.Considering total costs per patient case,PSI TKA is more expensive in comparison to CI TKA.Meta-analysis comparing total costs for PSI TKA,and CI TKA showed a significant higher cost for PSI TKA.CONCLUSION Cost for PSI and CI TKA can differ when considering distinct aspects of their implementation.Total costs per patient case are increased for PSI TKA when compared to CI TKA. 展开更多
关键词 Total knee arthroplasty Patient specific instrumentation Instrumentation for total knee arthroplasty cost-effectiveness Systematic review
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Ultrafast Response and Threshold Adjustable Intelligent Thermoelectric Systems for Next‑Generation Self‑Powered Remote IoT Fire Warning
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作者 Zhaofu Ding Gang Li +5 位作者 Yejun Wang Chunyu Du Zhenqiang Ye Lirong Liang Long‑Cheng Tang Guangming Chen 《Nano-Micro Letters》 SCIE EI CAS CSCD 2024年第11期413-428,共16页
Fire warning is vital to human life,economy and ecology.However,the development of effective warning systems faces great challenges of fast response,adjustable threshold and remote detecting.Here,we propose an intelli... Fire warning is vital to human life,economy and ecology.However,the development of effective warning systems faces great challenges of fast response,adjustable threshold and remote detecting.Here,we propose an intelligent self-powered remote IoT fire warning system,by employing single-walled carbon nanotube/titanium carbide thermoelectric composite films.The flexible films,prepared by a convenient solution mixing,display p-type characteristic with excellent high-temperature stability,flame retardancy and TE(power factor of 239.7±15.8μW m^(-1) K^(-2))performances.The comprehensive morphology and structural analyses shed light on the underlying mechanisms.And the assembled TE devices(TEDs)exhibit fast fire warning with adjustable warning threshold voltages(1–10 mV).Excitingly,an ultrafast fire warning response time of~0.1 s at 1 mV threshold voltage is achieved,rivaling many state-of-the-art systems.Furthermore,TE fire warning systems reveal outstanding stability after 50 repeated cycles and desired durability even undergoing 180 days of air exposure.Finally,a TED-based wireless intelligent fire warning system has been developed by coupling an amplifier,analogto-digital converter and Bluetooth module.By combining TE characteristics,high-temperature stability and flame retardancy with wireless IoT signal transmission,TE-based hybrid system developed here is promising for next-generation self-powered remote IoT fire warning applications. 展开更多
关键词 THERMOELECTRIC SELF-POWERED IoT fire warning Ultrafast response threshold adjustable
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Vector Dominance with Threshold Searchable Encryption (VDTSE) for the Internet of Things
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作者 Jingjing Nie Zhenhua Chen 《Computers, Materials & Continua》 SCIE EI 2024年第6期4763-4779,共17页
The Internet of Medical Things(IoMT)is an application of the Internet of Things(IoT)in the medical field.It is a cutting-edge technique that connects medical sensors and their applications to healthcare systems,which ... The Internet of Medical Things(IoMT)is an application of the Internet of Things(IoT)in the medical field.It is a cutting-edge technique that connects medical sensors and their applications to healthcare systems,which is essential in smart healthcare.However,Personal Health Records(PHRs)are normally kept in public cloud servers controlled by IoMT service providers,so privacy and security incidents may be frequent.Fortunately,Searchable Encryption(SE),which can be used to execute queries on encrypted data,can address the issue above.Nevertheless,most existing SE schemes cannot solve the vector dominance threshold problem.In response to this,we present a SE scheme called Vector Dominance with Threshold Searchable Encryption(VDTSE)in this study.We use a Lagrangian polynomial technique and convert the vector dominance threshold problem into a constraint that the number of two equal-length vectors’corresponding bits excluding wildcards is not less than a threshold t.Then,we solve the problem using the proposed technique modified in Hidden Vector Encryption(HVE).This technique makes the trapdoor size linear to the number of attributes and thus much smaller than that of other similar SE schemes.A rigorous experimental analysis of a specific application for privacy-preserving diabetes demonstrates the feasibility of the proposed VDTSE scheme. 展开更多
关键词 Internet of Things(IoT) Internet of Medical Things(IoMT) vector dominance with threshold searchable encryption(VDTSE) threshold comparison electronic healthcare
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Chalcogenide Ovonic Threshold Switching Selector
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作者 Zihao Zhao Sergiu Clima +4 位作者 Daniele Garbin Robin Degraeve Geoffrey Pourtois Zhitang Song Min Zhu 《Nano-Micro Letters》 SCIE EI CAS CSCD 2024年第5期1-40,共40页
Today’s explosion of data urgently requires memory technologies capable of storing large volumes of data in shorter time frames,a feat unattain-able with Flash or DRAM.Intel Optane,commonly referred to as three-dimen... Today’s explosion of data urgently requires memory technologies capable of storing large volumes of data in shorter time frames,a feat unattain-able with Flash or DRAM.Intel Optane,commonly referred to as three-dimensional phase change memory,stands out as one of the most promising candidates.The Optane with cross-point architecture is constructed through layering a storage element and a selector known as the ovonic threshold switch(OTS).The OTS device,which employs chalcogenide film,has thereby gathered increased attention in recent years.In this paper,we begin by providing a brief introduction to the discovery process of the OTS phenomenon.Subsequently,we summarize the key elec-trical parameters of OTS devices and delve into recent explorations of OTS materials,which are categorized as Se-based,Te-based,and S-based material systems.Furthermore,we discuss various models for the OTS switching mechanism,including field-induced nucleation model,as well as several carrier injection models.Additionally,we review the progress and innovations in OTS mechanism research.Finally,we highlight the successful application of OTS devices in three-dimensional high-density memory and offer insights into their promising performance and extensive prospects in emerging applications,such as self-selecting memory and neuromorphic computing. 展开更多
关键词 Non-volatile memory Ovonic threshold switch(OTS) CHALCOGENIDE SELECTOR
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Fractal model of spontaneous imbibition in low-permeability reservoirs coupled with heterogeneity of pore seepage channels and threshold pressure
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作者 Ming-Sheng Zuo Hao Chen +3 位作者 Xi-Liang Liu Hai-Peng Liu Yi Wu Xin-Yu Qi 《Petroleum Science》 SCIE EI CAS CSCD 2024年第2期1002-1017,共16页
Spontaneous imbibition(SI)is an important mechanism for enhancing oil recovery in low-permeability reservoirs.Due to the strong heterogeneity,and the non-Darcy flow,the construction of SI model for lowpermeability res... Spontaneous imbibition(SI)is an important mechanism for enhancing oil recovery in low-permeability reservoirs.Due to the strong heterogeneity,and the non-Darcy flow,the construction of SI model for lowpermeability reservoirs is extremely challenging.Commonly,traditional SI models based on single or averaged capillary tortuosity ignore the influence of heterogeneity of pore seepage channels and the threshold pressure(TP)on imbibition.Therefore,in this work,based on capillary model and fractal theory,a mathematical model of characterizing SI considering heterogeneity of pore seepage channels is established.On this basis,the threshold pressure was introduced to determine the pore radius at which the wetted phase can displace oil.The proposed new SI model was verified by imbibition experimental data.The study shows that for weakly heterogeneous cores with permeability of 0-1 m D,the traditional SI model can characterize the imbibition process relatively accurately,and the new imbibition model can increase the coefficient of determination by 1.05 times.However,traditional model has serious deviations in predicting the imbibition recovery for cores with permeability of 10-50 m D.The new SI model coupling with heterogeneity of pore seepage channels and threshold pressure effectively solves this problem,and the determination coefficient is increased from 0.344 to 0.922,which is increased by2.68 times.For low-permeability reservoirs,the production of the oil in transitional pores(0.01-0.1μm)and mesopores(0.1-1μm)significantly affects the imbibition recovery,as the research shows that when the heterogeneity of pore seepage channels is ignored,the oil recovery in transitional pores and mesopores decreases by 7.54%and 4.26%,respectively.Sensitivity analysis shows that increasing interfacial tension,decreasing contact angle,oil-water viscosity ratio and threshold pressure will increase imbibition recovery.In addition,there are critical values for the influence of these factors on the imbibition recovery,which provides theoretical support for surfactant optimization. 展开更多
关键词 Spontaneous imbibition Low-permeability reservoir Fractal model threshold pressure Capillary tube
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Cost-Effective Method of Gene Synthesis by Sequencing from Microchip-Derived Oligos for Droplet Cloning
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作者 Kimberly Wang 《Advances in Bioscience and Biotechnology》 CAS 2024年第8期474-485,共12页
Gene synthesis has provided important contributions in various fields including genomics and medicine. Current genes are 7 - 30 cents depending on the assembly and sequencing methods performed. Demand for gene synthes... Gene synthesis has provided important contributions in various fields including genomics and medicine. Current genes are 7 - 30 cents depending on the assembly and sequencing methods performed. Demand for gene synthesis has been increasing for the past few decades, yet available methods remain expensive. A solution to this problem involves microchip-derived oligonucleotides (oligos), an oligo pool with a substantial number of oligo fragments. Microchips have been proposed as a tool for gene synthesis, but this approach has been criticized for its high error rate during sequencing. This study tests a possible cost-effective method for gene synthesis utilizing fragment assembly and golden gate assembly, which can be employed for quicker manufacturing and efficient execution of genes in the near future. The droplet method was tested in two trials to determine the viability of the method through the accuracy of the oligos sequenced. A preliminary research experiment was performed to determine the efficacy of oligo lengths ranging from two to four overlapping oligos through Gibson assembly. Of the three oligo lengths tested, only two fragment oligos were correctly sequenced. Two fragment oligos were used for the second experiment, which determined the efficacy of the droplet method in reducing gene synthesis cost and speed. The first trial utilized a high-fidelity polymerase and resulted in 3% correctly sequenced oligos, so the second trial utilized a non-high-fidelity polymerase, resulting in 8% correctly sequenced oligos. After calculating, the cost of gene synthesis lowers down to 0.8 cents/base. The final calculated cost of 0.8 cents/base is significantly cheaper than other manufacturing costs of 7 - 30 cents/base. Reducing the cost of gene synthesis provides new insight into the cost-effectiveness of present technologies and protocols and has the potential to benefit the fields of bioengineering and gene therapy. 展开更多
关键词 cost-effectIVE Gene Synthesis MICROCHIP Oligo Droplet Cloning
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A study of the soil water potential threshold values to trigger irrigation of ‘Shimizu Hakuto’ peach at pivotal fruit developmental stages
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作者 Yusui Lou Yuepeng Han +4 位作者 Yubin Miao Hongquan Shang Zhongwei Lv Lei Wang Shiping Wang 《Horticultural Plant Journal》 SCIE CAS CSCD 2024年第2期376-386,共11页
Water management is an important practice that affects fruit size and quality.Effective implementation of irrigation scheduling requires knowledge of the appropriate indicators and thresholds,which are established man... Water management is an important practice that affects fruit size and quality.Effective implementation of irrigation scheduling requires knowledge of the appropriate indicators and thresholds,which are established manly based on the effects of water deficits on final fruit quality.Few studies have focused on the real-time effects of water status on fruit and shoot growth.To establish soil water potential (ψ_(soil)) thresholds to trigger irrigation of peach at pivotal fruit developmental stages,photogrammetry,^(13)C labelling,and other techniques were used in this study to investigate real-time changes in stem diameter,fruit projected area,net leaf photosynthetic rate (P_(n)),and allocation of photoassimilates to fruit under soil water potential conditions ranging from saturation to stress in 6-year-old Shimizu hakuto’peach.Stem growth,fruit growth,and P_n exhibited gradually decreasing sensitivity to water deficits during fruit developmental stages I,II,and III.Stem diameter growth was significantly inhibited whenψ_(soil)dropped to-8.5,-7.6,and-5.4 k Pa,respectively.Fruit growth rate was low,reaching zero when theψ_(soil)was-9.0 to-23.1,-14.9 to-21.4,and-16.5 to-23.3 k Pa,respectively,and P_ndecreased significantly when theψ_(soil)reached-24.2,-22.7,and-20.4 kPa,respectively.In addition,more photoassimilates were allocated to fruit under moderateψ_(soil)conditions (-10.1 to-17.0 k Pa) than under otherψ_(soil)values.Our results revealed threeψ_(soil)thresholds,-10.0,-15.0,and-15.0 kPa,suitable for triggering irrigation during stages I,II,and III,respectively.These thresholds can be helpful for controlling excessive tree vigor,maintaining rapid fruit growth and leaf photosynthesis,and promoting the allocation of more photoassimilates to fruit. 展开更多
关键词 PEACH Soil water potential Irrigation threshold Fruit expansion PHOTOSYNTHESIS
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Epidemic threshold influenced by non-pharmaceutical interventions in residential university environments
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作者 卢泽超 赵生妹 +1 位作者 束华中 巩龙延 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第2期551-556,共6页
The control of highly contagious disease spreading in campuses is a critical challenge.In residential universities,students attend classes according to a curriculum schedule,and mainly pack into classrooms,dining hall... The control of highly contagious disease spreading in campuses is a critical challenge.In residential universities,students attend classes according to a curriculum schedule,and mainly pack into classrooms,dining halls and dorms.They move from one place to another.To simulate such environments,we propose an agent-based susceptible–infected–recovered model with time-varying heterogeneous contact networks.In close environments,maintaining physical distancing is the most widely recommended and encouraged non-pharmaceutical intervention.It can be easily realized by using larger classrooms,adopting staggered dining hours,decreasing the number of students per dorm and so on.Their real-world influence remains uncertain.With numerical simulations,we obtain epidemic thresholds.The effect of such countermeasures on reducing the number of disease cases is also quantitatively evaluated. 展开更多
关键词 epidemic threshold susceptible-infected-recovered model non-pharmaceutical interventions time-varying heterogeneous contact networks
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Cost-effectiveness Analysis of Insulin Degludec and Liraglutide Injection in the Treatment of Type 2 Diabetes
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作者 Sun Quan Zhang Fang Dong Li 《Asian Journal of Social Pharmacy》 2023年第3期281-295,共15页
Objective To analyze the cost-effectiveness of insulin degludec and liraglutide injection(IDegLira)compared with insulin glargine plus insulin aspart(IGar plus IAsp)in the treatment of type 2 diabetes mellitus(T2DM)ba... Objective To analyze the cost-effectiveness of insulin degludec and liraglutide injection(IDegLira)compared with insulin glargine plus insulin aspart(IGar plus IAsp)in the treatment of type 2 diabetes mellitus(T2DM)based on the price of IDegLira before and after it was successfully admitted to the National Reimbursable Drug List(NRDL).Methods Cost and effectiveness parameters were obtained through systematic retrieval from PubMed,ScienceDirect,CNKI,and Wanfang database.A cost-effectiveness analysis(CEA)model was established to analyze the economics using IDegLira for T2DM patients with 1 to 5 years of medication.Results and Conclusion Before IDegLira was admitted to NRDL,its economic advantages over the IGlar plus Iasp regimen became more significant as patients’medication time prolonged.After being admitted to NRDL,with 1 year of medication,the medical cost of IDegLira decreased by 2853.91 yuan and the quality adjusted life years(QALY)increased by 0.12055 than IGar plus IAsp.The sensitivity analysis was highly consistent with the results of the baseline result.After being admitted to NRDL,for patients with T2DM who have poor blood glucose control,IDegLira is absolutely an economic advantage scheme compared with IGar plus IAsp. 展开更多
关键词 insulin degludec and liraglutide injection insulin glargine insulin aspart cost-effectiveness analysis
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CT Thresholds for Spinal Bone Mineral Attenuation to Prioritize Eligible Older Women for Osteoporosis Screening
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作者 Seo Yeon K. Orite Bryn Higuchi +1 位作者 Hyo-Chun Yoon Lana H. Gimber 《Open Journal of Radiology》 2024年第2期92-101,共10页
Introduction: Computed tomography (CT) measurements of bone mineral attenuation may be a useful means to identify older women who should be prioritized for bone mineral density screening. Methods: We compared bone min... Introduction: Computed tomography (CT) measurements of bone mineral attenuation may be a useful means to identify older women who should be prioritized for bone mineral density screening. Methods: We compared bone mineral attenuation as measured in the L1 vertebra of CT studies to the results of dual-energy x-ray absorptiometry (DEXA) studies to determine what CT attenuation thresholds might yield a reasonable combination of sensitivity and specificity for the detection of osteoporosis. The study was limited to women between the ages of 65 and 75 years who had a DEXA study and a CT that included the L1 or adjacent vertebra performed within 3 years of the DEXA study. Results: There were 1226 women in this study, of whom 452 (38%) had osteoporosis based on a T-score ≤ −2.5 by DEXA. There were 830 CT studies performed with contrast and 396 studies which were performed without contrast. There was a statistically significant difference in the mean HU of those studies performed without contrast compared to those with contrast (unenhanced mean 103 HU versus 125 HU, p < 0.001). Different CT attenuation thresholds provided the most appropriate combination of sensitivity and specificity for the detection of osteoporosis when comparing CT studies performed without or with IV contrast and when all the CT data were used in aggregate. Conclusion: Different thresholds appear necessary when using the mean CT vertebral attenuation to identify older women for preferential referral for DEXA studies. 展开更多
关键词 OSTEOPOROSIS Bone Mineral Attenuation CT threshold
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Evaluation of rainfall threshold models for debris flow initiation in the Jiangjia Gully,Yunnan Province,China
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作者 YANG Hongjuan ZHANG Shaojie +2 位作者 HU Kaiheng WEI Fangqiang LIU Yanhui 《Journal of Mountain Science》 SCIE CSCD 2024年第6期1799-1813,共15页
Systematically determining the discriminatory power of various rainfall properties and their combinations in identifying debris flow occurrence is crucial for early warning systems.In this study,we evaluated the discr... Systematically determining the discriminatory power of various rainfall properties and their combinations in identifying debris flow occurrence is crucial for early warning systems.In this study,we evaluated the discriminatory power of different univariate and multivariate rainfall threshold models in identifying triggering conditions of debris flow in the Jiangjia Gully,Yunnan Province,China.The univariate models used single rainfall properties as indicators,including total rainfall(R_(tot)),rainfall duration(D),mean intensity(I_(mean)),absolute energy(Eabs),storm kinetic energy(E_(s)),antecedent rainfall(R_(a)),and maximum rainfall intensity over various durations(I_(max_dur)).The evaluation reveals that the I_(max_dur)and Eabs models have the best performance,followed by the E_(s),R_(tot),and I_(mean)models,while the D and R_(a)models have poor performances.Specifically,the I_(max_dur)model has the highest performance metrics at a 40-min duration.We used logistic regression to combine at least two rainfall properties to establish multivariate threshold models.The results show that adding D or R_(a)to the models dominated by Eabs,E_(s),R_(tot),or I_(mean)generally improve their performances,specifically when D is combined with I_(mean)or when R_(a)is combined with Eabs or E_(s).Including R_(a)in the I_(max_dur)model,it performs better than the univariate I_(max_dur)model.A power-law relationship between I_(max_dur)and R_(a)or between Eabs and R_(a)has better performance than the traditional I_(mean)–D model,while the performance of the E_(s)–R_(a)model is moderate.Our evaluation reemphasizes the important role of the maximum intensity over short durations in debris flow occurrence.It also highlights the importance of systematically investigating the role of R_(a)in establishing rainfall thresholds for triggering debris flow.Given the regional variations in rainfall patterns worldwide,it is necessary to evaluate the findings of this study across diverse watersheds. 展开更多
关键词 Rainfall threshold Logistic regression Maximum rainfall intensity Absolute energy Antecedent rainfall
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Vehicle Abnormal Behavior Detection Based on Dense Block and Soft Thresholding
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作者 Yuanyao Lu Wei Chen +2 位作者 Zhanhe Yu Jingxuan Wang Chaochao Yang 《Computers, Materials & Continua》 SCIE EI 2024年第6期5051-5066,共16页
With the rapid advancement of social economies,intelligent transportation systems are gaining increasing atten-tion.Central to these systems is the detection of abnormal vehicle behavior,which remains a critical chall... With the rapid advancement of social economies,intelligent transportation systems are gaining increasing atten-tion.Central to these systems is the detection of abnormal vehicle behavior,which remains a critical challenge due to the complexity of urban roadways and the variability of external conditions.Current research on detecting abnormal traffic behaviors is still nascent,with significant room for improvement in recognition accuracy.To address this,this research has developed a new model for recognizing abnormal traffic behaviors.This model employs the R3D network as its core architecture,incorporating a dense block to facilitate feature reuse.This approach not only enhances performance with fewer parameters and reduced computational demands but also allows for the acquisition of new features while simplifying the overall network structure.Additionally,this research integrates a self-attentive method that dynamically adjusts to the prevailing traffic conditions,optimizing the relevance of features for the task at hand.For temporal analysis,a Bi-LSTM layer is utilized to extract and learn from time-based data nuances.This research conducted a series of comparative experiments using the UCF-Crime dataset,achieving a notable accuracy of 89.30%on our test set.Our results demonstrate that our model not only operates with fewer parameters but also achieves superior recognition accuracy compared to previous models. 展开更多
关键词 Vehicle abnormal behavior deep learning ResNet dense block soft thresholding
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Impacts of proppant distribution on development of tight oil reservoirs with threshold pressure gradient
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作者 Ming Yue Wei-Yao Zhu +3 位作者 Fei-Fei Gou Tian-Ru Song Yu-Chun You Qi-Tao Zhang 《Petroleum Science》 SCIE EI CAS CSCD 2024年第1期445-457,共13页
Field evidence indicates that proppant distribution and threshold pressure gradient have great impacts on well productivity.Aiming at the development of unconventional oil reservoirs in Triassic Chang-7 Unit,Ordos Bas... Field evidence indicates that proppant distribution and threshold pressure gradient have great impacts on well productivity.Aiming at the development of unconventional oil reservoirs in Triassic Chang-7 Unit,Ordos Basin of China,we presented an integrated workflow to investigate how(1)proppant placement in induced fracture and(2)non-linear flow in reservoir matrix would affect well productivity and fluid flow in the reservoir.Compared with our research before(Yue et al.,2020),here we extended this study into the development of multi-stage fractured horizontal wells(MFHWs)with large-scale complicated fracture geometry.The integrated workflow is based on the finite element method and consists of simulation models for proppant-laden fluid flow,fracture flow,and non-linear seepage flow,respectively.Simulation results indicate that the distribution of proppant inside the induced cracks significantly affects the productivity of the MFHW.When we assign an idealized proppant distribution instead of the real distribution,there will be an overestimation of 44.98%in daily oil rate and 30.63%in cumulative oil production after continuous development of 1000 days.Besides,threshold pressure gradient(TPG)also significantly affects the well performance in tight oil reservoirs.If we simply apply linear Darcy’s law to the reservoir matrix,the overall cumulative oil production can be overrated by 77%after 1000 days of development.In general,this research provides new insights into the development of tight oil reservoirs with TPG and meanwhile reveals the significance of proppant distribution and non-linear fluid flow in the production scenario design. 展开更多
关键词 Proppant distribution Tight oil reservoir Multi-stage fractured horizontal well threshold pressure gradient Moving boundary
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AMicroseismic Signal Denoising Algorithm Combining VMD and Wavelet Threshold Denoising Optimized by BWOA
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作者 Dijun Rao Min Huang +2 位作者 Xiuzhi Shi Zhi Yu Zhengxiang He 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第10期187-217,共31页
The denoising of microseismic signals is a prerequisite for subsequent analysis and research.In this research,a new microseismic signal denoising algorithm called the Black Widow Optimization Algorithm(BWOA)optimized ... The denoising of microseismic signals is a prerequisite for subsequent analysis and research.In this research,a new microseismic signal denoising algorithm called the Black Widow Optimization Algorithm(BWOA)optimized VariationalMode Decomposition(VMD)jointWavelet Threshold Denoising(WTD)algorithm(BVW)is proposed.The BVW algorithm integrates VMD and WTD,both of which are optimized by BWOA.Specifically,this algorithm utilizes VMD to decompose the microseismic signal to be denoised into several Band-Limited IntrinsicMode Functions(BLIMFs).Subsequently,these BLIMFs whose correlation coefficients with the microseismic signal to be denoised are higher than a threshold are selected as the effective mode functions,and the effective mode functions are denoised using WTD to filter out the residual low-and intermediate-frequency noise.Finally,the denoised microseismic signal is obtained through reconstruction.The ideal values of VMD parameters and WTD parameters are acquired by searching with BWOA to achieve the best VMD decomposition performance and solve the problem of relying on experience and requiring a large workload in the application of the WTD algorithm.The outcomes of simulated experiments indicate that this algorithm is capable of achieving good denoising performance under noise of different intensities,and the denoising performance is significantly better than the commonly used VMD and Empirical Mode Decomposition(EMD)algorithms.The BVW algorithm is more efficient in filtering noise,the waveform after denoising is smoother,the amplitude of the waveform is the closest to the original signal,and the signal-to-noise ratio(SNR)and the root mean square error after denoising are more satisfying.The case based on Fankou Lead-Zinc Mine shows that for microseismic signals with different intensities of noise monitored on-site,compared with VMD and EMD,the BVW algorithm ismore efficient in filtering noise,and the SNR after denoising is higher. 展开更多
关键词 Variational mode decomposition microseismic signal DENOISING wavelet threshold denoising black widow optimization algorithm
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Properties of radiation defects and threshold energy of displacement in zirconium hydride obtained by new deep-learning potential
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作者 王玺 唐孟 +3 位作者 蒋明璇 陈阳春 刘智骁 邓辉球 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第7期456-465,共10页
Zirconium hydride(ZrH_(2)) is an ideal neutron moderator material. However, radiation effect significantly changes its properties, which affect its behavior and the lifespan of the reactor. The threshold energy of dis... Zirconium hydride(ZrH_(2)) is an ideal neutron moderator material. However, radiation effect significantly changes its properties, which affect its behavior and the lifespan of the reactor. The threshold energy of displacement is an important quantity of the number of radiation defects produced, which helps us to predict the evolution of radiation defects in ZrH_(2).Molecular dynamics(MD) and ab initio molecular dynamics(AIMD) are two main methods of calculating the threshold energy of displacement. The MD simulations with empirical potentials often cannot accurately depict the transitional states that lattice atoms must surpass to reach an interstitial state. Additionally, the AIMD method is unable to perform largescale calculation, which poses a computational challenge beyond the simulation range of density functional theory. Machine learning potentials are renowned for their high accuracy and efficiency, making them an increasingly preferred choice for molecular dynamics simulations. In this work, we develop an accurate potential energy model for the ZrH_(2) system by using the deep-potential(DP) method. The DP model has a high degree of agreement with first-principles calculations for the typical defect energy and mechanical properties of the ZrH_(2) system, including the basic bulk properties, formation energy of point defects, as well as diffusion behavior of hydrogen and zirconium. By integrating the DP model with Ziegler–Biersack–Littmark(ZBL) potential, we can predict the threshold energy of displacement of zirconium and hydrogen in ε-ZrH_(2). 展开更多
关键词 zirconium hydride deep learning potential radiation defects molecular dynamics threshold energy of displacement
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The Toxic Effects of Strong Chlorin Disinfectant on Mangroves and Emission Thresholds
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作者 Yunan Yang Nan Zhou Xinyu Liu 《Open Journal of Ecology》 2024年第2期114-124,共11页
In this study, based on the simulated discharge results of chemical disinfectants, hypocotyl germination concentration gradient pre-test and concentration gradient determination experiment were set up respectively. La... In this study, based on the simulated discharge results of chemical disinfectants, hypocotyl germination concentration gradient pre-test and concentration gradient determination experiment were set up respectively. Laboratory cultivation was conducted to compare and analyze the root germination and germination indexes, three mangrove hypocotyls of Kandelia candel (Linn.) Druce, Ceriopstagal C.B. Rob. and Bruguiera sexangula var. Rhynchopetalas’ efficiency of cumulative root germination, cumulative germination and the cumulative expansion of the second pair of leaves, one-way analysis of variance was used to obtain the tolerance threshold of three mangrove hypocotyls to strong chlorin disinfectant. The study determined that the by-products of strong chlorin disinfectant, the toxic threshold concentrations of Kandelia candel (Linn.) Druce, Ceriopstagal C.B. Rob. and Bruguiera sexangula var. rhynchopetala are close to 0.55 mg/L, 0.55 mg/L and 0.25 mg/L, respectively. This concentration range is lower than the average concentration of 1.183 mg/L of active chlorine emitted from strong chlorine concentrate during pond clearing in high-level shrimp ponds, indicating that transient emissions of strong chlorine concentrate during pond clearing can have a toxic effect on mangrove plants. The strength of tolerance of the embryonic axes of the three mangrove species to effective chlorine contamination was, Ceriopstagal C.B. Rob. stronger than Bruguiera sexangula var. rhynchopetala, and Kandelia candel (Linn.) Druce is the weakest. 展开更多
关键词 Strong Chlorin Toxicity threshold Germination of Mangrove Hypocotyls One-Way Analysis of Variance
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The effects of population aging on industrial structure upgrading:Empirical analysis of provincial and threshold characteristics in China
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作者 Mao Hu Linyu Xiao Hong Qiu 《Chinese Journal of Population,Resources and Environment》 2024年第3期356-366,共11页
Global population aging trends are intensifying,presenting multifaceted economic and social challenges for countries worldwide.As the world’s largest developing country,China has entered a phase of extreme demographi... Global population aging trends are intensifying,presenting multifaceted economic and social challenges for countries worldwide.As the world’s largest developing country,China has entered a phase of extreme demographic aging,posing significant questions about its impact on the ongoing upgrading of industrial structures.How does this demographic shift influence the upgrading of industrial structures,and does technological innovation mitigate or exacerbate this impact?The empirical results indicate that population aging impedes upgrading the industrial structure,while technological innovation positively affects the relationship between the two.Moreover,using technological innovation as a threshold variable,the impact of population aging on industrial structure upgrading evolves in a“gradient”manner from“impediment”to“insignificant”to“promotion”as the technological innovation levels increase.These findings offer practical guidance for tailoring industrial policies to different stages of technological advancement. 展开更多
关键词 Population aging Technological innovation level Industrial structure upgrading Panel threshold models Instrumental variable method
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