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Loss Rate Estimation of Yield and Output Value of Tobacco Leaf Infected by Tobacco Blown Spot (Alternaria alternata) 被引量:3
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作者 余清 《Plant Diseases and Pests》 CAS 2010年第6期23-27,63,共6页
[Objective] The paper was to study the effect of tobacco blown spot on the yield and output value of tobacco leaf.[Method]The upper,middle and lower leaves in tobacco plant were selected during the harvest period of t... [Objective] The paper was to study the effect of tobacco blown spot on the yield and output value of tobacco leaf.[Method]The upper,middle and lower leaves in tobacco plant were selected during the harvest period of tobacco to carry out loss rate estimation of yield and output value of tobacco leaf caused by different disease levels of brown spot.Regression correlation analysis was also conducted.[Result]The disease levels of brown spot had extremely significant strong negative correlation with single leaf weight of tobacco leaf,and it had extremely significant strong positive correlation with the loss rate of single leaf weight.The increase speed of loss rate of single leaf weight of middle and upper leaves was obviously faster than that of lower leaves.The loss rates of single leaf weight of upper,middle and lower leaves were 3.18%-28.95%,3.43%-28.88% and 10.07%-26.90%,respectively.The higher the disease level of blown spot was,the lower the yield and output value of tobacco leaf was,and the corresponding loss rate was also higher.Correlation analysis showed that the disease level of blown spot had extremely significant strong negative correlation with the yield and output value of tobacco leaf,and it had extremely significant strong positive correlation with the loss rate of yield and output value.The negative impact of blown spot on the output value of tobacco leaf was far greater than that on the yield.The highest loss rate of the yield of tobacco leaf was 28.56%,while the highest loss rate of output value reached 89.67%.[Conclusion] The study provided theoretical basis for accurately holding the critical period for the control of blown spot,thus reducing the damage on tobacco leaf and improving the output value of tobacco leaf. 展开更多
关键词 Tobacco brown spot Single-leaf weight Yield of tobacco leaf Output value of tobacco leaf Loss rate estimation
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Physics-informed neural network approach for heat generation rate estimation of lithium-ion battery under various driving conditions 被引量:8
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作者 Hui Pang Longxing Wu +2 位作者 Jiahao Liu Xiaofei Liu Kai Liu 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2023年第3期1-12,I0001,共13页
Accurate insight into the heat generation rate(HGR) of lithium-ion batteries(LIBs) is one of key issues for battery management systems to formulate thermal safety warning strategies in advance.For this reason,this pap... Accurate insight into the heat generation rate(HGR) of lithium-ion batteries(LIBs) is one of key issues for battery management systems to formulate thermal safety warning strategies in advance.For this reason,this paper proposes a novel physics-informed neural network(PINN) approach for HGR estimation of LIBs under various driving conditions.Specifically,a single particle model with thermodynamics(SPMT) is first constructed for extracting the critical physical knowledge related with battery HGR.Subsequently,the surface concentrations of positive and negative electrodes in battery SPMT model are integrated into the bidirectional long short-term memory(BiLSTM) networks as physical information.And combined with other feature variables,a novel PINN approach to achieve HGR estimation of LIBs with higher accuracy is constituted.Additionally,some critical hyperparameters of BiLSTM used in PINN approach are determined through Bayesian optimization algorithm(BOA) and the results of BOA-based BiLSTM are compared with other traditional BiLSTM/LSTM networks.Eventually,combined with the HGR data generated from the validated virtual battery,it is proved that the proposed approach can well predict the battery HGR under the dynamic stress test(DST) and worldwide light vehicles test procedure(WLTP),the mean absolute error under DST is 0.542 kW/m^(3),and the root mean square error under WLTP is1.428 kW/m^(3)at 25℃.Lastly,the investigation results of this paper also show a new perspective in the application of the PINN approach in battery HGR estimation. 展开更多
关键词 Lithium-ion batteries Physics-informed neural network Bidirectional long-term memory Heat generation rate estimation Electrochemical model
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Human Respiration Rate Estimation Using Ultra-wideband Distributed Cognitive Radar System 被引量:1
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作者 Predrag Rapajic 《International Journal of Automation and computing》 EI 2008年第4期325-333,共9页
It has been shown that remote monitoring of pulmonary activity can be achieved using ultra-wideband (UWB) systems, which shows promise in home healthcare,rescue,and security applications.In this paper,we first present... It has been shown that remote monitoring of pulmonary activity can be achieved using ultra-wideband (UWB) systems, which shows promise in home healthcare,rescue,and security applications.In this paper,we first present a multi-ray propagation model for UWB signal,which is traveling through the human thorax and is reflected on the air/dry-skin/fat/muscle interfaces,A geometry-based statistical channel model is then developed for simulating the reception of UWB signals in the indoor propagation environment.This model enables replication of time-varying multipath profiles due to the displacement of a human chest.Subsequently, a UWB distributed cognitive radar system (UWB-DCRS) is developed for the robust detection of chest cavity motion and the accurate estimation of respiration rate.The analytical framework can serve as a basis in the planning and evaluation of future rheasurement programs.We also provide a case study on how the antenna beamwidth affects the estimation of respiration rate based on the proposed propagation models and system architecture. 展开更多
关键词 Medical and patient monitoring sensing technologies and signal processing vital sign ULTRA-WIDEBAND distributed cog-nitive radar respiration rate estimation.
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Error Rate Estimation in Quantum Key Distribution with Finite Resources
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作者 卢钊 史建红 李风光 《Communications in Theoretical Physics》 SCIE CAS CSCD 2017年第4期360-364,共5页
The goal of quantum key distribution(QKD) is to generate secret key shared between two distant players,Alice and Bob. We present the connection between sampling rate and erroneous judgment probability when estimating ... The goal of quantum key distribution(QKD) is to generate secret key shared between two distant players,Alice and Bob. We present the connection between sampling rate and erroneous judgment probability when estimating error rate with random sampling method, and propose a method to compute optimal sampling rate, which can maximize final secure key generation rate. These results can be applied to choose the optimal sampling rate and improve the performance of QKD system with finite resources. 展开更多
关键词 quantum key distribution error rate estimation optimal sampling rate final secure key generationrate
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A new compensation method for angular rate estimation of non-gyro inertial measurement unit
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作者 丁明理 梁廷伟 王倩 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2009年第6期761-765,共5页
A new compensation method for angular rate estimation of non-gyro inertial measurement unit (NGIMU) is proposed in terms of the existence of aecelerometer mounting error, which seriously affects the precision of nav... A new compensation method for angular rate estimation of non-gyro inertial measurement unit (NGIMU) is proposed in terms of the existence of aecelerometer mounting error, which seriously affects the precision of navigation parameter estimation. Using the accelerometer output error function, the algorithm compensates the posture parameters in the traditional algorithm of angular rate estimation to reduce the accelerometer mounting error. According to the traditional aceelerometer configurations, a novel nine-accelerometer confi-guration of NGIMU is presented with its mathematic model constructed. The semi-hardware simulations of the proposed algorithm are investigated based on the presented NGIMU configuration, and the results show the effectivity of the new algorithm. 展开更多
关键词 inertial navigation non-gyro angular rate estimation mounting location
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Impact of creatinine methodology on glomerular filtration rate estimation in diabetes
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作者 Marijana Vucic Lovrencic Vanja Radisic Biljak +2 位作者 Kristina Blaslov Sandra Bozicevic Lea Smircic Duvnjak 《World Journal of Diabetes》 SCIE CAS 2017年第5期222-229,共8页
AIM To evaluate the influence of creatinine methodology on the performance of chronic kidney disease(CKD)-Epidemiology Collaboration Group-calculated estimated glomerular filtration rate(CKD-EPI-eGFR) for CKD diagnosi... AIM To evaluate the influence of creatinine methodology on the performance of chronic kidney disease(CKD)-Epidemiology Collaboration Group-calculated estimated glomerular filtration rate(CKD-EPI-eGFR) for CKD diagnosis/staging in a large cohort of diabetic patients. METHODS Fasting blood samples were taken from diabetic patients attending our clinic for their regular annual examination, including laboratory measurement of serum creatinine and eGFR.RESULTS Our results indicated an overall excellent agreement in CKD staging(kappa = 0.918) between the Jaffé serum creatinine-and enzymatic serum creatinine-based CKDEPI-eGFR, with 9% of discordant cases. As compared to the enzymatic creatinine, the majority of discordances(8%) were positive, i.e., associated with the more advanced CKD stage re-classification, whereas only 1% of cases were negatively discordant if Jaffé creatinine was used for eGFR calculation. A minor proportion of the discordant cases(3.5%) were re-classified into clinically relevant CKD stage indicating mildly to moderately decreased kidney function(< 60 m L/min per 1.73 m^2). Significant acute and chronic hyperglycaemia, assessedas plasma glucose and Hb A1 c levels far above the recommended glycaemic goals, was associated with positively discordant cases. Due to a very low frequency, positive discordance is not likely to present a great burden for the health-care providers, while intensified medical care may actually be beneficial for the small number of discordant patients. On the other hand, a very low proportion of negatively discordant cases(1%) at the 60 m L/min per 1.73 m^2 eGFR level indicate a negligible possibility to miss the CKD diagnosis, which could be the most prominent clinical problem affecting patient care, considering high risk of CKD for adverse patient outcomes. CONCLUSION This study indicate that compensated Jaffé creatinine procedure, in spite of the glucose-dependent bias, is not inferior to enzymatic creatinine in CKD diagnosis/staging and therefore may provide a reliable and cost-effective tool for the renal function assessment in diabetic patients. 展开更多
关键词 DIABETES Estimated glomerular filtration rate Chronic kidney disease-Epidemiology Collaboration Group CREATININE Enzymatic method Chronic kidney disease IMPACT Compensated Jaffé method
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RETF: a TCP-Friendly Control Scheme Based on Rate Estimation for Stored Video 被引量:1
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作者 ZHANG Yu-qing,CAI An-ni,SUN Jing-ao(School of Telecommunication Engineering,Beijing University of Posts and Telecommunications, Beijing 100876, P.R. China) 《The Journal of China Universities of Posts and Telecommunications》 EI CSCD 2003年第4期5-10,共6页
In this paper, a TCP-friendly rate control algorithm is proposed for storedMPEG2 layered video. In this algorithm, RTT is observed at the receiver through the use of probe APPpackets, and the control interval is chose... In this paper, a TCP-friendly rate control algorithm is proposed for storedMPEG2 layered video. In this algorithm, RTT is observed at the receiver through the use of probe APPpackets, and the control interval is chosen based on the self-similar nature of MPEG2 traffic . Inaddition, the estimated receiving rate is used as an indication to the network status when nopacket loss is detected . In our simulations, a friendliness of 0.94 is obtained, and the videoquality fluctuations are acceptable with this control algorithm. 展开更多
关键词 TCP-FRIENDLY rate estimation congestion control
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Estimation of rate constants for polymerization based on Monte Carlo simulation
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作者 罗正鸿 詹晓力 阳永荣 《Journal of Shanghai University(English Edition)》 CAS 2006年第3期274-276,共3页
The application of Monte Carlo method in estimating rate constants for polymerization was described, A general program for Monte Carlo simulation was determined first according to the elementary reactions, after which... The application of Monte Carlo method in estimating rate constants for polymerization was described, A general program for Monte Carlo simulation was determined first according to the elementary reactions, after which the rate constants could be automatically adjusted and optimized through comparing of experimental and simulated data with an error expression that meeted a given minimum criterion. Such a process made the rate constants to be estimated without kinetic model in advance. The technique was applied to estimate the rate constants of the bulk polymerization of styrene catalyzed by the rare earth catalyst. The esthnated results showed the Monte Carlo method was feasible and effective for estimating rate constants in polymerization engineering. 展开更多
关键词 Monte Carlo simulation rate constants estimation polymerization.
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Chronic kidney disease in geriatric patients:Estimating glomerular filtration rate in older patients with comorbidities
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作者 Guido Gembillo Luca Soraci Domenico Santoro 《World Journal of Nephrology》 2025年第2期178-181,共4页
Aging is an inevitable process that is usually measured by chronological age,with people aged 65 and over being defined as"older individuals".There is disagreement in the current scientific literature regard... Aging is an inevitable process that is usually measured by chronological age,with people aged 65 and over being defined as"older individuals".There is disagreement in the current scientific literature regarding the best methods to estimate glomerular filtration rate(eGFR)in older adults.Several studies suggest the use of an age-adjusted definition to improve accuracy and avoid overdiagnosis.In contrast,some researchers argue that such changes could complicate the classification of chronic kidney disease(CKD).Several formulas,including the Modification of Diet in Renal Disease,CKD-Epidemiology Collaboration,and Cockcroft-Gault equations,are used to estimate eGFR.However,each of these formulas has significant limitations when applied to older adults,primarily due to sarcopenia and malnutrition,which greatly affect both muscle mass and creatinine levels.Alternative formulas,such as the Berlin Initiative Study and the Full Age Spectrum equations,provide more accurate estimates of values for older adults by accounting for age-related physiological changes.In frail older adults,the use of cystatin C leads to better eGFR calculations to assess renal function.Accurate eGFR measurements improve the health of older patients by enabling better medication dosing.A thorough approach that includes multiple calibrated diagnostic methods and a detailed geriatric assessment is necessary for the effective management of kidney disease and other age-related conditions in older adults. 展开更多
关键词 Chronic kidney disease Estimated glomerular filtration rate Renal alterations Geriatric patients Chronic Kidney Disease-Epidemiology Collaboration Modification of Diet in Renal Disease Cockcroft-Gault formula Berlin initiative study Full age spectrum equation
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Arbitrary Decode-Forward Relaying with Re-Encoded Bits Selection Strategy for Polar Codes 被引量:1
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作者 Di Guan Kai Niu Chao Dong 《China Communications》 SCIE CSCD 2023年第8期153-162,共10页
In this paper,we propose an arbitrary decode-forward single-relay scheme for finite blocklength polar codes,which can be applied to the general symmetric discrete memoryless relay channel with orthogonal receiver comp... In this paper,we propose an arbitrary decode-forward single-relay scheme for finite blocklength polar codes,which can be applied to the general symmetric discrete memoryless relay channel with orthogonal receiver components.The relay node decodes the received message.The relay node selectively re-encodes the message and transmits it to the destination node.Furthermore,in order to minimize the upper-bound of the block error probability,we propose a selection strategy to decide the proper re-encoded bit set by the relay.Simulation results are presented to illustrate the improvement in decoding performance of the proposed scheme compared to conventional relay schemes in both additive white Gaussian noise(AWGN)channel and Rayleigh fading channel(RFC). 展开更多
关键词 polar codes decode-and-forward relaying arbitrary relay channel block error rate estimation
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Estimating glomerular filtration rate in kidney transplantation:Still searching for the best marker 被引量:1
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作者 Josefina Santos La Salete Martins 《World Journal of Nephrology》 2015年第3期345-353,共9页
Kidney transplantation is the treatment of choice for end-stage renal disease. The evaluation of graft function is mandatory in the management of renal transplant recipients. Glomerular filtration rate (GFR), is gen... Kidney transplantation is the treatment of choice for end-stage renal disease. The evaluation of graft function is mandatory in the management of renal transplant recipients. Glomerular filtration rate (GFR), is generally considered the best index of graft function and also a predictor of graft and patient survival. However GFR measurement using inulin clearance, the gold standard for its measurement and exogenous markers such as radiolabeled isotopes (51Cr EDTA, 99mTc DTPA or 125I Iothalamate) and non-radioactive contrast agents (Iothalamate or Iohexol), is laborious as well as expensive, being rarely used in clinical practice. Therefore, endogenous markers, such as serum creatinine or cystatin C, are used to estimate kidney function, and equations using these markers adjusted to other variables, mainly demographic, are an attempt to improve accuracy in estimation of GFR (eGFR). Nevertheless, there is some concern about the inability of the available eGFR equations to accurately identify changes in GFR, in kidney transplant recipients. This article will review and discuss the performance and limitations of these endogenous markers and their equations as estimators of GFR in the kidney transplant recipients, and their ability in predicting signifcant clinical outcomes. 展开更多
关键词 Glomerular fltration rate estimation CREATININE Cystatin C Kidney transplantation Clinical outcomes
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Monthly advance rate estimation of hard rock tunnel boring machine based on rock mass classification and data augmentation
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作者 Honggan Yu Yin Bo +3 位作者 Quansheng Liu Xuhui Yang Shuzhan Xu Xing Huang 《Underground Space》 2025年第4期175-192,共18页
Accurately estimating the monthly advance rate of hard rock tunnel boring machine is of great significance for construction method selection,machine type determination,and project planning.However,current researches m... Accurately estimating the monthly advance rate of hard rock tunnel boring machine is of great significance for construction method selection,machine type determination,and project planning.However,current researches mainly focus on estimating the advance rate during construction,and few studies can estimate the advance rate from the entire tunnel scale.To overcome above shortcomings,a monthly advance rate estimation method based on rock mass classification and data augmentation is proposed.Firstly,56 cases of tunnel boring machine are collected,and proportions of all rock mass grades in basic quality system of the entire tunnel are selected as main inputs of the model.Then,a two-stage data augmentation method based on synthetic minority over-sampling technique and modified auxiliary classifier generative adversarial network is developed.Finally,monthly advance rate estimation models based on machine learning and augmented datasets are established.The results show that the proposed method can accurately estimate the monthly advance rate and the data augmentation method can significantly augment the dataset.The average accuracy of the models is improved by 44.82%after data augmentation.Extreme gradient boosting model performs the best,with an accuracy of 90.31%.Therefore,the proposed method can accurately estimate the monthly advance rate of tunnel boring machine from the tunnel scale and has essential academic and engineering value. 展开更多
关键词 Tunnel boring machine Advance rate estimation Rock mass classification Data augmentation Machine learning
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Machine learning-based comparison of factors influencing estimated glomerular filtration rate in Chinese women with or without nonalcoholic fatty liver 被引量:2
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作者 I-Chien Chen Lin-Ju Chou +2 位作者 Shih-Chen Huang Ta-Wei Chu Shang-Sen Lee 《World Journal of Clinical Cases》 SCIE 2024年第15期2506-2521,共16页
BACKGROUND The prevalence of non-alcoholic fatty liver(NAFLD)has increased recently.Subjects with NAFLD are known to have higher chance for renal function impairment.Many past studies used traditional multiple linear ... BACKGROUND The prevalence of non-alcoholic fatty liver(NAFLD)has increased recently.Subjects with NAFLD are known to have higher chance for renal function impairment.Many past studies used traditional multiple linear regression(MLR)to identify risk factors for decreased estimated glomerular filtration rate(eGFR).However,medical research is increasingly relying on emerging machine learning(Mach-L)methods.The present study enrolled healthy women to identify factors affecting eGFR in subjects with and without NAFLD(NAFLD+,NAFLD-)and to rank their importance.AIM To uses three different Mach-L methods to identify key impact factors for eGFR in healthy women with and without NAFLD.METHODS A total of 65535 healthy female study participants were enrolled from the Taiwan MJ cohort,accounting for 32 independent variables including demographic,biochemistry and lifestyle parameters(independent variables),while eGFR was used as the dependent variable.Aside from MLR,three Mach-L methods were applied,including stochastic gradient boosting,eXtreme gradient boosting and elastic net.Errors of estimation were used to define method accuracy,where smaller degree of error indicated better model performance.RESULTS Income,albumin,eGFR,High density lipoprotein-Cholesterol,phosphorus,forced expiratory volume in one second(FEV1),and sleep time were all lower in the NAFLD+group,while other factors were all significantly higher except for smoking area.Mach-L had lower estimation errors,thus outperforming MLR.In Model 1,age,uric acid(UA),FEV1,plasma calcium level(Ca),plasma albumin level(Alb)and T-bilirubin were the most important factors in the NAFLD+group,as opposed to age,UA,FEV1,Alb,lactic dehydrogenase(LDH)and Ca for the NAFLD-group.Given the importance percentage was much higher than the 2nd important factor,we built Model 2 by removing age.CONCLUSION The eGFR were lower in the NAFLD+group compared to the NAFLD-group,with age being was the most important impact factor in both groups of healthy Chinese women,followed by LDH,UA,FEV1 and Alb.However,for the NAFLD-group,TSH and SBP were the 5th and 6th most important factors,as opposed to Ca and BF in the NAFLD+group. 展开更多
关键词 Non-alcoholic fatty liver Estimated glomerular filtration rate Machine learning Chinese women
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Establishing the presence or absence of chronic kidney disease:Uses and limitations of formulas estimating the glomerular filtration rate 被引量:8
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作者 Ahmed Alaini Deepak Malhotra +6 位作者 Helbert Rondon-Berrios Christos P Argyropoulos Zeid J Khitan Dominic SC Raj Mark Rohrscheib Joseph I Shapiro Antonios H Tzamaloukas 《World Journal of Methodology》 2017年第3期73-92,共20页
The development of formulas estimating glomerular filtration rate(eG FR) from serum creatinine and cystatin C and accounting for certain variables affecting the production rate of these biomarkers, including ethnicity... The development of formulas estimating glomerular filtration rate(eG FR) from serum creatinine and cystatin C and accounting for certain variables affecting the production rate of these biomarkers, including ethnicity, gender and age, has led to the current scheme of diagnosing and staging chronic kidney disease(CKD),which is based on e GFR values and albuminuria.This scheme has been applied extensively in various populations and has led to the current estimates of prevalence of CKD. In addition, this scheme is applied in clinical studies evaluating the risks of CKD and the efficacy of various interventions directed towards improving its course. Disagreements between creatinine-based and cystatin-based e GFR values and between e GFR values and measured GFR have been reported in various cohorts. These disagreements are the consequence of variations in the rate of production and in factors, other than GFR, affecting the rate of removal of creatinine and cystatin C. The disagreements create limitations for all e GFR formulas developed so far. The main limitations are low sensitivity in detecting early CKD in several subjects, e.g., those with hyperfiltration, and poor prediction of the course of CKD. Research efforts in CKD are currently directed towards identification of biomarkers that are better indices of GFR than the current biomarkers and,particularly, biomarkers of early renal tissue injury. 展开更多
关键词 Chronic kidney disease Serum creatinine Creatinine clearance Creatinine excretion Estimated glomerular filtration rate Cystatin C Renal imaging HYPERFILTRATION Biomarkers of chronic kidney disease
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Difference between CKD-EPI and MDRD equations in calculating glomerular filtration rate in patients with cirrhosis 被引量:1
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作者 Yu-Wei Chen Han-Hsiang Chen +3 位作者 Tsang-En Wang Ching-Wei Chang Chen-Wang Chang Chih-Jen Wu 《World Journal of Gastroenterology》 SCIE CAS CSCD 2011年第40期4532-4538,共7页
AIM:To evaluate the difference between the performance of the (CKD-EPI) and Modification of Diet in Renal Disease (MDRD) equations in cirrhotic patients. METHODS: From Jan 2004 to Oct 2008, 4127 cirrhotic patients wer... AIM:To evaluate the difference between the performance of the (CKD-EPI) and Modification of Diet in Renal Disease (MDRD) equations in cirrhotic patients. METHODS: From Jan 2004 to Oct 2008, 4127 cirrhotic patients were reviewed. Patients with incomplete data with respect to renal function were excluded; thus, a total of 3791 patients were included in the study. The glomerular filtration rate (GFR) was estimated by the 4-variable MDRD (MDRD-4), 6-variable MDRD (MDRD-6), and CKD-EPI equations.RESULTS:When serum creatinine was 0.7-6.8 mg/dL and 0.6-5.3 mg/dL in men and women, respectively, a significantly lower GFR was estimated by the MDRD-6 than by the CKD-EPI. Similar GFRs were calculated by both equations when creatinine was > 6.9 mg/dL and > 5.4 mg/dL in men and women, respectively. In predicting in-hospital mortality, estimated GFR obtained by the MDRD-6 showed better accuracy [81.72%; 95% confidence interval (CI), 0.94-0.95] than that obtained by the MDRD-4 (80.22%; 95%CI, 0.96-0.97), CKD-EPI (79.93%; 95%CI, 0.96-0.96), and creatinine (77.50%; 95%CI, 2.27-2.63). CONCLUSION: GFR calculated by the 6-variable MDRD equation may be closer to the true GFR than that calculated by the CKD-EPI equation. 展开更多
关键词 Chronic Kidney Disease Epidemiology Col-laboration Estimated glomerular filtration rate LIVERCIRRHOSIS Modification of Diet in Renal Disease Renalfunction
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Is an estimated glomerular filtration rate better than creatinine to be incorporated into the end-stage liver disease score? 被引量:1
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作者 Chih-Jen Wu Han-Hsiang Chen +3 位作者 Ching-Wei Chang Tsang-En Wang Chen-Wang Chang Tsang-En Wang 《World Journal of Hepatology》 CAS 2012年第11期291-298,共8页
AIM: To incorporate estimated glomerular filtration rate (eGFR) into the model for end-stage liver disease (MELD) score to evaluate the predictive value. METHODS: From January 2004 to October 2008, the records of 4127... AIM: To incorporate estimated glomerular filtration rate (eGFR) into the model for end-stage liver disease (MELD) score to evaluate the predictive value. METHODS: From January 2004 to October 2008, the records of 4127 admitted cirrhotic patients were reviewed. Patients who survived and were followed up as outpatients were defined as survivors and their most recent available laboratory data were collected. Patients whose records indicated death at any time during the hospital stay were defined as non-survivors (in-hospital mortality). Patients with incomplete data or with cirrhosis due to a congenital abnormality such as primary biliary cirrhosis were excluded; thus, a total of 3857 patients were enrolled in the present study. The eGFR, which was calculated by using either the modification of diet in renal disease (MDRD) equation or the chronic kidney disease epidemiology collaboration (CKD-EPI) equation, was incorporated into the MELD score after adjustment with the original MELD equation by logistic regression analysis [bilirubin and international normalized ratio (INR) were set at 1.0 for values less than 1.0]. RESULTS: Patients defined as survivors were significantly younger, had a lower incidence of hepatoma, lower Child-Pugh and MELD scores, and better renal function. The underlying causes of cirrhosis were very different from those in Western countries. In Taiwan, most cirrhotic patients were associated with the hepatitis virus, especially hepatitis B. There were 16 parameters included in univariate logistic regression analysis to predict in-hospital mortality and those with significant predicting values were included in further multivariate analysis. Both 4-variable MDRD eGFR and 6-variable MDRD eGFR, rather than creatinine, were significant predictors of in-hospital mortality. Three new equations were constructed (MELD-MDRD-4, MELD-MDRD-6, MELD-CKD-EPI). As expected, original MELD score was a significant predictor of in-hospital mortality (odds ratio = 1.25, P < 0.001). MELD-MDRD-4 excluded serum creatinine, with the coefficients refit among the remaining 3 variables, i.e., total bilirubin, INR and 4-variable MDRD eGFR. This model represented an exacerbated outcome over MELD score, as suggested by a decrease in chi-square (2161.45 vs 2198.32) and an increase in -2 log (likelihood) (2810.77 vs 2773.90). MELD-MDRD-6 included 6-variable MDRD eGFR as one of the variables and showed an improvement over MELD score, as suggested by an increase in chi-square (2293.82 vs 2198.32) and a decrease in -2 log (likelihood) (2810.77 vs 2664.79). Finally, when serum creatinine was replaced by CKD-EPI eGFR, it showed a slight improvement compared to the original MELD score (chi-square: 2199.16, -2 log (likelihood): 2773.07). In the receiver-operating characteristic curve, the MELD-MDRD-6 score showed a marginal improvement in area under the curve (0.909 vs 0.902), sensitivity (0.854 vs 0.819) and specificity (0.818 vs 0.839) compared to the original MELD equation. In patients with a different eGFR, the MELD-MDRD-6 equation showed a better predictive value in patients with eGFR ≥ 90, 60-89, 30-59 and 15-29. CONCLUSION: Incorporating eGFR obtained by the 6-variable MDRD equation into the MELD score showed an equal predictive performance in in-hospital mortality compared to a creatinine-based MELD score. 展开更多
关键词 Liver cirrhosis Estimated glomerular filtration rate End-stage liver disease Modification of diet in renal disease Renal function
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Detection of decline in estimated glomerular filtration rate in patients with type 2 diabetes by cystatin C-based equations 被引量:2
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作者 Tam Thai Thanh Tran Tien Kim Ha +2 位作者 Nhut Minh Phan Minh Van Le Tin Hoang Nguyen 《World Journal of Nephrology》 2024年第4期103-116,共14页
BACKGROUND Aging population is a significant issue in Viet Nam and across the globe.Elderly individuals are at higher risk of chronic kidney disease(CKD),especially those with diabetes.Several studies found that the e... BACKGROUND Aging population is a significant issue in Viet Nam and across the globe.Elderly individuals are at higher risk of chronic kidney disease(CKD),especially those with diabetes.Several studies found that the estimated glomerular filtration rate(eGFR)determined using creatinine-based equations was not as accurate as that determined using cystatin C-based equations.Cystatin C-based equations may be beneficial in elderly patients with an age-associated decline in kidney function.Early determination of eGFR decline and associated factors would aid in appropriate interventions to improve kidney function in elderly patients with diabetes.AIM To determine the utility of cystatin C-based equations in early detection of eGFR decline and to explore factors associated with eGFR decline in elderly patients with diabetes.METHODS This cross-sectional study included 93 participants aged≥60 years evaluated in Can Tho University of Medicine and Pharmacy Hospital between October 2022 and July 2023,including 47 and 46 participants with and without diabetes respectively,according to the American Diabetes Association criteria for diabetes.The kappa coefficient,Student’s t,Mann-Whitney,χ2,Pearson’s correlation,multivariate logistic regression,and multiple linear regression analyses were employed.RESULTS The eGFRs were lower with the cystatin C-based equations than with the creatinine-based equations.Good agreement was found between the Modification of Diet in Renal Disease(MDRD)and CKD Epidemiology Collaboration(CKD-EPI)2021 creatinine-cystatin C equations(kappa=0.66).In the diabetes group,30%of the participants had low eGFR.Both plasma glucose and glycated hemoglobin were associated with an increased risk of eGFR decline(P<0.05)and negatively correlated with eGFR(P=0.001).By multivariate logistic regression,total cholesterol,and exercise were independently associated with low eGFR.By multiple linear regression,higher plasma glucose levels were correlated with lower eGFR(P=0.026,r=-0.366).CONCLUSION Cystatin C-based equations were superior in the early detection of a decline in eGFR,and the MDRD equation may be considered as an alternative to the CKD-EPI 2021 creatinine-cystatin C equation.Exercise,plasma glucose,and total cholesterol were independently associated with eGFR in patients with diabetes. 展开更多
关键词 Cystatin C Estimated glomerular filtration rate ELDERLY DIABETES NEPHROLOGY Kidney function
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Nonparametric estimation of employee stock options
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作者 傅强 《Journal of Chongqing University》 CAS 2006年第4期239-243,共5页
We proposed a new model to price employee stock options (ESOs). The model is based on nonparametric statistical methods with market data. It incorporates the kernel estimator and employs a three-step method to modif... We proposed a new model to price employee stock options (ESOs). The model is based on nonparametric statistical methods with market data. It incorporates the kernel estimator and employs a three-step method to modify Black- Scholes formula. The model overcomes the limits of Black-Scholes formula in handling option prices with varied volatility. It disposes the effects of ESOs self-characteristics such as non-tradability, the longer term for expiration, the eady exercise feature, the restriction on shorting selling and the employee's risk aversion on risk neutral pricing condition, and can be applied to ESOs valuation with the explanatory variable in no matter the certainty case or random case. 展开更多
关键词 option pricing employee stock options exit rate nonparametic estimation kernel estimator
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Estimating glomerular filtration rate preoperatively for patients undergoing hepatectomy
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作者 Yoshimi Iwasaki Tokihiko Sawada +6 位作者 Shozo Mori Yukihiro Iso Masato Katoh Kyu Rokkaku Junji Kita Mitsugi Shimoda Keiichi Kubota 《World Journal of Gastroenterology》 SCIE CAS CSCD 2009年第18期2252-2257,共6页
AIM:To compare creatinine clearance(Ccr) with estimated glomerular filtration rate(eGFR) in preoperative renal function tests in patients undergoing hepatectomy.METHODS:The records of 197 patients undergoing hepatecto... AIM:To compare creatinine clearance(Ccr) with estimated glomerular filtration rate(eGFR) in preoperative renal function tests in patients undergoing hepatectomy.METHODS:The records of 197 patients undergoing hepatectomy between August 2006 and August 2008 were studied,and preoperative Ccr,a three-variable equation for eGFR(eGFR3) and a five-variable equation for eGFR(eGFR5) were calculated.Abnormal values were defined as Ccr < 50 mL/min,eGFR3 and eGFR5 < 60 mL/min per 1.73 m2.The maximum increases in the postoperative serum creatinine(post Cr) level and postoperative rate of increase in the serum Cr level(post Cr rate) were compared.RESULTS:There were 37 patients(18.8%) with abnormal Ccr,31(15.7%) with abnormal eGFR3,and 40(20.3%) with abnormal eGFR5.Although there were no significant differences in the post Cr rate between patients with normal and abnormal Ccr,eGFR3 and eGFR5 values,the post Cr level was significantly higher in patients with eGFR3 and eGFR5 abnormality than in normal patients(P < 0.0001).Post Cr level tended to be higher in patients with Ccr abnormality(P = 0.0936 and P = 0.0875,respectively).CONCLUSION:eGFR5 and the simpler eGFR3,rather than Ccr,are recommended as a preoperative renal function test in patients undergoing hepatectomy. 展开更多
关键词 Estimated glomerular filtration rate Creatinine clearance test HEPATECTOMY Renal functiontest
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Risk estimation of chronic kidney disease in a leptospirosis endemic area: A case-control study from south Andaman Islands of India
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作者 Ambreen Fatema Manjunatha Ramu Paluru Vijayachari 《Asian Pacific Journal of Tropical Medicine》 SCIE CAS 2023年第10期463-471,共9页
Objective:To estimate the risk of chronic kidney disease in patients with leptospirosis.Methods:All reported(41890)and later confirmed leptospirosis(1990)cases from 2010-2020 were traced by universal sampling.386 Labo... Objective:To estimate the risk of chronic kidney disease in patients with leptospirosis.Methods:All reported(41890)and later confirmed leptospirosis(1990)cases from 2010-2020 were traced by universal sampling.386 Laboratory-confirmed leptospirosis cases were enrolled and 413 age,gender,area,and occupation matched healthy persons were included as controls.Variables including socio-demographic characteristics,medical history,and health-related behaviours were compared between the two groups and association between these variables and reduced estimated glomerular filtration rate(eGFR)was analyzed with multiple linear regression.Results:The median of eGFR was 49.0(27.0,75.0)mL/min/1.73 m^(2) in the cases and 96.0(72.0,121.0)mL/min/1.73 m^(2) in the controls,showing significant differences(P<0.001).Bivariate analysis showed that leptospirosis seropositivitiy,repeat leptospirosis infection,diabetes,male gender,working in field(sun exposure),COVID-19 infection and smoking had statistically significant association with reduced eGFR.Leptospirosis seropositivity had negative effects on eGFR.Multiple linear regression confirmed that leptospirosis seropositivity had negative effects on eGFR(unstandardised β coefficients=−30.86,95%CI−49.7 to−11.9,P<0.001).Conclusions:Chronic kidney disease is a complex disease with multiple risk factors involved.Exposure to leptospirosis is one of the essential factors in accelerating its progression. 展开更多
关键词 Chronic kidney disease Endemic leptospirosis Estimated glomerular filtration rate(eGFR)
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