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Cumulative effects of excess high-normal alanine aminotransferase levels in relation to new-onset metabolic dysfunction-associated fatty liver disease in China 被引量:7
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作者 Jing-Feng Chen Zhuo-Qing Wu +5 位作者 Hao-Shuang Liu Su Yan You-Xiang Wang Miao Xing Xiao-Qin Song Su-Ying Ding 《World Journal of Gastroenterology》 SCIE CAS 2024年第10期1346-1357,共12页
BACKGROUND Within the normal range,elevated alanine aminotransferase(ALT)levels are associated with an increased risk of metabolic dysfunction-associated fatty liver disease(MAFLD).AIM To investigate the associations ... BACKGROUND Within the normal range,elevated alanine aminotransferase(ALT)levels are associated with an increased risk of metabolic dysfunction-associated fatty liver disease(MAFLD).AIM To investigate the associations between repeated high-normal ALT measurements and the risk of new-onset MAFLD prospectively.METHODS A cohort of 3553 participants followed for four consecutive health examinations over 4 years was selected.The incidence rate,cumulative times,and equally and unequally weighted cumulative effects of excess high-normal ALT levels(ehALT)were measured.Cox proportional hazards regression was used to analyse the association between the cumulative effects of ehALT and the risk of new-onset MAFLD.RESULTS A total of 83.13%of participants with MAFLD had normal ALT levels.The incidence rate of MAFLD showed a linear increasing trend in the cumulative ehALT group.Compared with those in the low-normal ALT group,the multivariate adjusted hazard ratios of the equally and unequally weighted cumulative effects of ehALT were 1.651[95%confidence interval(CI):1.199-2.273]and 1.535(95%CI:1.119-2.106)in the third quartile and 1.616(95%CI:1.162-2.246)and 1.580(95%CI:1.155-2.162)in the fourth quartile,respectively.CONCLUSION Most participants with MAFLD had normal ALT levels.Long-term high-normal ALT levels were associated with a cumulative increased risk of new-onset MAFLD. 展开更多
关键词 Metabolic dysfunction-associated fatty liver disease High-normal alanine aminotransferase level cumulative effect Cox proportional hazards regression Cohort study
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The Cumulative Method for Multiplication and Division
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作者 Muna Mohammed Hammuda 《Applied Mathematics》 2024年第5期349-354,共6页
This paper provides a method of the process of computation called the cumulative method, it is based upon repeated cumulative process. The cumulative method is being adapted to the purposes of computation, particularl... This paper provides a method of the process of computation called the cumulative method, it is based upon repeated cumulative process. The cumulative method is being adapted to the purposes of computation, particularly multiplication and division. The operations of multiplication and division are represented by algebraic formulas. An advantage of the method is that the cumulative process can be performed on decimal numbers. The present paper aims to establish a basic and useful formula valid for the two fundamental arithmetic operations of multiplication and division. The new cumulative method proved to be more flexible and made it possible to extend the multiplication and division based on repeated addition/subtraction to decimal numbers. 展开更多
关键词 Multiplication and Division cumulative Method Repeated Process Decimal Numbers
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Study on cumulative effects of biological craniocerebral trauma under repeated blast
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作者 Xingyuan Huang Bingchen Xia +3 位作者 Lijun Chang Zhikang Liao Hui Zhao Zhihua Cai 《Theoretical & Applied Mechanics Letters》 CAS CSCD 2024年第3期174-183,共10页
Repeated blast impacts on personnel in explosive environments can exacerbate craniocerebral trauma.Most existing studies focus on the injury effects of a single blast,lacking in-depth analysis on the injury effects an... Repeated blast impacts on personnel in explosive environments can exacerbate craniocerebral trauma.Most existing studies focus on the injury effects of a single blast,lacking in-depth analysis on the injury effects and cumulative effects of repeated blasts.Therefore,rats were used as the experimental samples to suffer from explosion blasts with different peak air overpressures(167 kPa~482 kPa)and varying number of repeated blasts.The cumulative effect of craniocerebral trauma was most pronounced for moderate repeated blast,showing approximately 95%increase of trauma severity with penta blast,and an approximately 85%increase of trauma severity with penta minor blast.The cumulative effect of craniocerebral trauma from severe,repeated blast has a smaller rate of change compared to the other two conditions.The severity of trauma from penta blast increased by approximately 69%compared to a single blast.Comprehensive physiological,pathological and biochemical analysis show that the degree of neurological trauma caused by repeated blasts is higher than that of single blasts,and the pathological trauma to brain tissue is more extensive and severe.The trauma degree remains unchanged after double blast,increases by one grade after triple or quadruple blast,and increases by two grades after penta blast. 展开更多
关键词 Repeated blast Craniocerebral trauma Trauma severity grade cumulative effects
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Development of a novel critical nitrogen concentration-cumulative transpiration curve for optimizing nitrogen management under varying irrigation conditions in winter wheat
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作者 Tianyang Ye Yu Zhang +9 位作者 Jingyan Xuan Xintian Wang Yang Li Junhao Xu Liujun Xiao Leilei Liu Liang Tang Weixing Cao Bing Liu Yan Zhu 《The Crop Journal》 SCIE CSCD 2024年第4期1242-1251,共10页
Accurate nitrogen(N)nutrition diagnosis is essential for improving N use efficiency in crop production.The widely used critical N(Nc)dilution curve traditionally depends solely on agronomic variables,neglecting crop w... Accurate nitrogen(N)nutrition diagnosis is essential for improving N use efficiency in crop production.The widely used critical N(Nc)dilution curve traditionally depends solely on agronomic variables,neglecting crop water status.With three-year field experiments with winter wheat,encompassing two irrigation levels(rainfed and irrigation at jointing and anthesis)and three N levels(0,180,and 270 kg ha1),this study aims to establish a novel approach for determining the Nc dilution curve based on crop cumulative transpiration(T),providing a comprehensive analysis of the interaction between N and water availability.The Nc curves derived from both crop dry matter(DM)and T demonstrated N concentration dilution under different conditions with different parameters.The equation Nc=6.43T0.24 established a consistent relationship across varying irrigation regimes.Independent test results indicated that the nitrogen nutrition index(NNI),calculated from this curve,effectively identifies and quantifies the two sources of N deficiency:insufficient N supply in the soil and insufficient soil water concentration leading to decreased N availability for root absorption.Additionally,the NNI calculated from the Nc-DM and Nc-T curves exhibited a strong negative correlation with accumulated N deficit(Nand)and a positive correlation with relative grain yield(RGY).The NNI derived from the Nc-T curve outperformed the NNI derived from the Nc-DM curve concerning its relationship with Nand and RGY,as indicated by larger R2 values and smaller AIC.The novel Nc curve based on T serves as an effective diagnostic tool for assessing winter wheat N status,predicting grain yield,and optimizing N fertilizer management across varying irrigation conditions.These findings would provide new insights and methods to improve the simulations of water-N interaction relationship in crop growth models. 展开更多
关键词 Crop dry matter Crop cumulative transpiration Bayesian statistical model Critical nitrogen dilution curve Nitrogen nutrition index
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Cumulative Air Quality Impacts from Twenty-Two Major Power Plants
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作者 Md M.Karim Navin Bindra Arub Masud 《Journal of Environmental Science and Engineering(A)》 CAS 2024年第1期1-14,共14页
Cumulative assessment is a tool for the project developer to try and take into consideration not only their contribution to cumulative impacts but also other projects and external factors that may place their developm... Cumulative assessment is a tool for the project developer to try and take into consideration not only their contribution to cumulative impacts but also other projects and external factors that may place their developments at risk.This study assessed the cumulative impacts of air emissions from 22 major power plants in southeast Bangladesh planned to generate 21,550 MW of electricity.It also includes anticipated growth in small to medium size industries,brickfields,highway traffic,inland water transport,transhippers,jetty,and vessel transports used for transporting fuel resources for these power plants.A 50 km by 50 km airshed is considered for air quality modeling.Cumulative analysis indicates that predicted MGLCs(Maximum Ground Level Concentrations)of NO2 and CO are complying with both Bangladesh NAAQS(National Ambient Air Quality Standards)and WBG(World Bank Group)Guidelines.The daily average MGLC of PM_(2.5)(62.45µg/m^(3))from all sources complies with NAAQS,however,exceeds the WBG Guidelines.Annual PM_(2.5) concentration(15.45µg/m^(3))exceeds NAAQS and WBG Guidelines.The PM10 concentration complies with the NAAQS for both 24-hour and annual averaging times.Annual average concentration(23.12µg/m^(3))exceeds WBG Guidelines.Daily average SO2 concentration(102.49µg/m^(3))complies with the NAAQS however,it exceeds the WBG guideline values.High concentrations of PM_(2.5) and SO2 are due to the contribution of transboundary emissions and secondary pollutants in the atmosphere.This dispersion modeling outcome can be used by the policymakers for the pollution reduction strategy. 展开更多
关键词 CIA(cumulative Impact Assessment) dispersion modeling power generation Bangladesh.
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Master Curve Method of Cumulative Damage for Prediction of Service Life
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作者 沈庭芳 赵伯华 《Journal of Beijing Institute of Technology》 EI CAS 1999年第1期109-113,共5页
Aim To study the theory and method for the prediction of service life of solid rocket propellant grain. Methods With the aid of discontiguous diagnostic technology and method of accumulated damage using accelerated... Aim To study the theory and method for the prediction of service life of solid rocket propellant grain. Methods With the aid of discontiguous diagnostic technology and method of accumulated damage using accelerated aging or heat air oven, the aging isotherms for void content versus aging time were determined. According to the principle of time temperature equivalence the viscoelastic master curve for the prediction of service life were obtained. Results and Conclusion The service life of HMX CMDB solid rocket propellant grain were obtained. Because the critical storage life is measured, the accuracy of predicting the service life of the grain has been increased greatly. 展开更多
关键词 void content thermal aging cumulative damage service life
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Cumulative impact of dam constructions on streamflow and sediment regime in lower reaches of the Jinsha River, China 被引量:7
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作者 HUANG Xiao-rong GAO Lin-yun +1 位作者 YANG Peng-peng XI Yuan-yuan 《Journal of Mountain Science》 SCIE CSCD 2018年第12期2752-2765,共14页
The cumulative effect of cascade hydropower stations on river ecological environment has been widely concerned because of the significant streamflow hydrology change induced by dam constructions. The characteristics o... The cumulative effect of cascade hydropower stations on river ecological environment has been widely concerned because of the significant streamflow hydrology change induced by dam constructions. The characteristics of the change in the lower reaches of the Jinsha River, China are analyzed based on long-term(1952–2015) hydrological and sedimentological data. The averaging coefficient, reservoir regulation coefficient(RRC), incoming sediment coefficient(ISC), and sediment transport modulus(STM), which reflect the variation of streamflow and sediment regimes, are defined and calculated. The results show that the construction and regulation of reservoirs reduces flow in flood season, increases flow in dry season, significantly altering the monthly discharge regimes. These alterations also led directly to changes in the timing of extreme flows at Pingshan Station. The monthly flow records at the basin outlet are reconstructed using stepwise regression, to reduce reservoir impacts. Comparisons of observed and reconstructed monthly flows demonstrate that the previous studies overestimated the cumulative effects of cascade reservoirs on flow processes. Furthermore, this study clearly illustrates that the reduction in sediment trapping and sediment transportation capacity together lead to the sharp reduction in annual sediment yield at the Pingshan Station. The earlier constructed reservoirs have more obvious effects on the ISC and STM than the more recent reservoirs and the effect of sediment trapping is related to reservoir location, on the main stream versus tributaries. 展开更多
关键词 CASCADE RESERVOIRS cumulative effect HYDROLOGICAL REGIME Sediment load Jinsha River
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A CUMULATIVE FATIGUE DAMAGE RULE UNDER THE ALTERNATIVE OF CORROSION OR CYCLIC LOADING 被引量:4
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作者 W.X. Yao 《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 2007年第1期65-71,共7页
Fatigue damage increases with the applied loading cycles in a cumulative manner and the material deteriorates with the corrosion time. A cumulative fatigue damage rule under the alternative of corrosion or cyclic load... Fatigue damage increases with the applied loading cycles in a cumulative manner and the material deteriorates with the corrosion time. A cumulative fatigue damage rule under the alternative of corrosion or cyclic loading was proposed. The specimens of aluminum alloy LY12-CZ soaked in corrosive liquid for different times were tested under the constant amplitude cyclic loading to obtain S-N curves. The test was carried out to verify the proposed cumulative fatigue damage rule under the different combinations among corrosion time, loading level, and the cycle numbers. It was shown that the predicted residual fatigue lives showed a good agreement with the experimental results and the proposed rule was simple and can be easily adopted. 展开更多
关键词 CORROSION FATIGUE cumulative fatigue damage rule Miner's rule
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Cumulative second-harmonic generation of Lamb waves propagating in a two-layered solid plate 被引量:2
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作者 项延训 邓明晰 《Chinese Physics B》 SCIE EI CAS CSCD 2008年第11期4232-4241,共10页
The physical process of cumulative second-harmonic generation of Lamb waves propagating in a two-layered solid plate is presented by using the second-order perturbation and the technique of nonlinear reflection of aco... The physical process of cumulative second-harmonic generation of Lamb waves propagating in a two-layered solid plate is presented by using the second-order perturbation and the technique of nonlinear reflection of acoustic waves at an interface. In general, the cumulative second-harmonic generation of a dispersive guided wave propagation does not occur. However, the present paper shows that the second-harmonic of Lamb wave propagation arising from the nonlinear interaction of the partial bulk acoustic waves and the restriction of the three boundaries of the solid plates does have a cumulative growth effect if some conditions are satisfied. Through boundary condition and initial condition of excitation, the analytical expression of cumulative second-harmonic of Lamb waves propagation is determined. Numerical results show the cumulative effect of Lamb waves on second-harmonic field patterns. 展开更多
关键词 Lamb waves second harmonics cumulative effect layered plates
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Evaluation of Inference Adequacy in Cumulative Logistic Regression Models:An Empirical Validation of ISW-Ridge Relationships 被引量:3
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作者 Cheng-Wu CHEN Hsien-Chueh Peter YANG +2 位作者 Chen-Yuan CHEN Alex Kung-Hsiung CHANG Tsung-Hao CHEN 《China Ocean Engineering》 SCIE EI 2008年第1期43-56,共14页
Internal solitary wave propagation over a submarine ridge results in energy dissipation, in which the hydrodynamic interaction between a wave and ridge affects marine environment. This study analyzes the effects of ri... Internal solitary wave propagation over a submarine ridge results in energy dissipation, in which the hydrodynamic interaction between a wave and ridge affects marine environment. This study analyzes the effects of ridge height and potential energy during wave-ridge interaction with a binary and cumulative logistic regression model. In testing the Global Null Hypothesis, all values are p 〈0.001, with three statistical methods, such as Likelihood Ratio, Score, and Wald. While comparing with two kinds of models, tests values obtained by cumulative logistic regression models are better than those by binary logistic regression models. Although this study employed cumulative logistic regression model, three probability functions p^1, p^2 and p^3, are utilized for investigating the weighted influence of factors on wave reflection. Deviance and Pearson tests are applied to cheek the goodness-of-fit of the proposed model. The analytical results demonstrated that both ridge height (X1 ) and potential energy (X2 ) significantly impact (p 〈 0. 0001 ) the amplitude-based refleeted rate; the P-values for the deviance and Pearson are all 〉 0.05 (0.2839, 0.3438, respectively). That is, the goodness-of-fit between ridge height ( X1 ) and potential energy (X2) can further predict parameters under the scenario of the best parsimonious model. Investigation of 6 predictive powers ( R2, Max-rescaled R^2, Sorners' D, Gamma, Tau-a, and c, respectively) indicate that these predictive estimates of the proposed model have better predictive ability than ridge height alone, and are very similar to the interaction of ridge height and potential energy. It can be concluded that the goodness-of-fit and prediction ability of the cumulative logistic regression model are better than that of the binary logistic regression model. 展开更多
关键词 binary logistic regression cumulative logistic regression model GOODNESS-OF-FIT internal solitary wave amplitude-based transmission rate
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Correlation between the cumulative analgesic effect of electroacupuncture intervention and synaptic plasticity of hypothalamic paraventricular nucleus neurons in rats with sciatica 被引量:6
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作者 Qiuling Xu Tao Liu +4 位作者 Shuping Chen Yonghui Gao Junying Wang Lina Qiao Junling Liu 《Neural Regeneration Research》 SCIE CAS CSCD 2013年第3期218-225,共8页
In the present study, a rat model of chronic neuropathic pain was established by ligation of the sciatic nerve and a model of learning and memory impairment was established by ovariectomy to investigate the analgesic ... In the present study, a rat model of chronic neuropathic pain was established by ligation of the sciatic nerve and a model of learning and memory impairment was established by ovariectomy to investigate the analgesic effect of repeated electroacupuncture stimulation at bilateral Zusanfi (ST36) and Yanglingquan (GB34). In addition, associated synaptic changes in neurons in the paraventricular nucleus of the hypothalamus were examined. Results indicate that the thermal pain threshold (paw withdrawal latency) was significantly increased in rats subjected to 2-week electroacupuncture intervention compared with 2-day electroacupuncture, but the analgesic effect was weakened remarkably in ovariectomized rats with chronic constrictive injury. 2-week electroacupuncture intervention substantially reversed the chronic constrictive injury-induced increase in the synaptic cleft width and thinning of the postsynaptic density. These findings indicate that repeated electroacupuncture at bilateral Zusanfi and Yanglingquan has a cumulative analgesic effect and can effectively relieve chronic neuropathic pain by remodeling the synaptic structure of the hypothalamic paraventricular nucleus. 展开更多
关键词 neural regeneration acupuncture and moxibustion Chronic neuropathic pain electroacupuncture acupuncture analgesia cumulative effect synaptic plasticity HYPOTHALAMUS learning and memory NEUROBIOLOGY grants-supported paper photographs-containing paper neuroregeneration
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The cumulative analgesic effect of repeated electroacupuncture involves synaptic remodeling in the hippocampal CA3 region 被引量:5
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作者 Qiulinq Xu Tao Liu +4 位作者 Shuping Chen Yonghui Gao Junying Wang Lina Qiao Junling Liu 《Neural Regeneration Research》 SCIE CAS CSCD 2012年第18期1378-1385,共8页
In the present study, we examined the analgesic effect of repeated electroacupuncture at bilateral Zusanfi (ST36) and Yanglingquan (GB34) once a day for 14 consecutive days in a rat model of chronic sciatic nerve ... In the present study, we examined the analgesic effect of repeated electroacupuncture at bilateral Zusanfi (ST36) and Yanglingquan (GB34) once a day for 14 consecutive days in a rat model of chronic sciatic nerve constriction injury-induced neuropathic pain. In addition, concomitant changes in calcium/calmodulin-dependent protein kinase II expression and synaptic ultrastructure of neurons in the hippocampal CA3 region were examined. The thermal pain threshold (paw withdrawal latency) was increased significantly in both groups at 2 weeks after electroacupuncture intervention compared with 2 days of electroacupuncture. In ovariectomized rats with chronic constriction injury, the analgesic effect was significantly reduced. Electroacupuncture for 2 weeks significantly diminished the injury-induced increase in synaptJc cleft width and thinning of the postsynaptJc density, and it significantly suppressed the down-regulation of intracellular calcium/ calmodulin-dependent protein kinase II expression in the hippocampal CA3 region. Repeated electroacupuncture intervention had a cumulative analgesic effect on injury-induced neuropathic pain reactions, and it led to synaptic remodeling of hippocampal neurons and upregulated calcium/calmodulin-dependent protein kJnase II expression in the hippocampal CA3 region. 展开更多
关键词 chronic neuropathic pain acupuncture analgesia cumulative effect synaptic plasticity hippocampal CA3 region calcium/calmodulin-dependent protein kinase II NEUROBIOLOGY ELECTROACUPUNCTURE neural regeneration
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Near-optimal cumulative longitude low-thrust orbit transfer 被引量:2
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作者 Yue Xincheng Yang Ying Geng Zhiyong 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2009年第6期1271-1277,共7页
The indirect method for the continuous low-thrust near minimum cumulative longitude orbit transfer problem is addressed.The movement of the satellite is described by the Gauss equation using the modified equinoctial e... The indirect method for the continuous low-thrust near minimum cumulative longitude orbit transfer problem is addressed.The movement of the satellite is described by the Gauss equation using the modified equinoctial elements and replacing time as the system independent variable by the cumulative longitude.The maximum principle is adapted to design the optimal control in order to minimize the final cumulative longitude, and the twopoint-boundary-value problem is derived from the orbit transfer problem.The single shooting method is applied in a numerical experiment, and the simulations demonstrate that the orbit transfer mission is fulfilled and the product of the maximal thrust and the minimum cumulative longitude is near constant. 展开更多
关键词 minimum cumulative longitude orbit transfer continuous thrust maximum principle shooting method.
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Cumulative Live Birth Rate after Three Ovarian Stimulation IVF Cycles for Poor Ovarian Responders According to the Bologna Criteria 被引量:2
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作者 柯慧 陈薪 +3 位作者 刘玉东 叶德盛 何于夏 陈士岭 《Journal of Huazhong University of Science and Technology(Medical Sciences)》 SCIE CAS 2013年第3期418-422,共5页
Summary: This study explored the cumulative live birth rate after three ovarian stimulation in vitro fer- tilization (IVF) cycles for poor ovarian responders according to the Bologna criteria. In this retrospec- ti... Summary: This study explored the cumulative live birth rate after three ovarian stimulation in vitro fer- tilization (IVF) cycles for poor ovarian responders according to the Bologna criteria. In this retrospec- tive cohort study, 479 poor ovarian responders according to the Bologna criteria in the first ovarian stimulation IVF cycle between July 2006 and January 2012 in our IVF centre were included. The cu- mulative live birth rate was calculated by optimistic and pessimistic methods. The cumulative live birth rate after three ovarian stimulation IVF cycles for poor ovarian responders according to the Bologna criteria was 12.7%-20.5%. The three-cycle cumulative live birth rate was 18.5%--24.5%, 13.2%-27.4% and 8.6%-14.9% for poor responders aged ≤35 years, 36-39 years and 〉40 years, re- spectively. In conclusion, poor responders according to the Bologna criteria can receive an acceptable cumulative live birth, rate after three ovarian stimulation IVF cycles, especially poor responders aged 〈40 years. 展开更多
关键词 ovarian stimulation in vitro fertilization Bologna criteria poor responders cumulative live birth
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The Impact of Meteorological Factors on the Short-term Cumulative Effect of Air Particulate in Tianjin 被引量:1
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作者 Wang Wei Liu Lili Wang Yan 《Meteorological and Environmental Research》 CAS 2019年第2期27-32,40,共7页
In order to reveal the rapid increase mechanism of particulate concentration in short time,a notion of short-term cumulative effect of air particulate is defined as the significant increase of pollutant concentration ... In order to reveal the rapid increase mechanism of particulate concentration in short time,a notion of short-term cumulative effect of air particulate is defined as the significant increase of pollutant concentration in a short time under the condition of breeze,stable weather and constant emission caused by human being's activities. Subsequently,an index of short-term cumulative effect is established with air diffusive equation,and then the macro-scale meteorological situation and micro-scale factors of forming the short-term cumulative effect are discussed with the observation data. The macro-scale meteorological variables contain upper-level weather situations and surface weather situations. The micro-scale factors mainly include the boundary-layer height and boundary-layer stability. The analyses show that boundary-layer factors and weather variables have a significant influence on the short-term cumulative effect. The notion of short-term cumulative effect will play an important role in interpreting the severe pollution weather. 展开更多
关键词 AIR PARTICULATE SHORT-TERM cumulative Effect METEOROLOGICAL factor cumulative index
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Seasonal Cumulative Effect of Ural Blocking Episodes on the Frequent Cold events in China during the Early Winter of 2020/21 被引量:9
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作者 Yao YAO Wenqi ZHANG +2 位作者 Dehai LUO Linhao ZHONG Lin PEI 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2022年第4期609-624,共16页
Starting in mid-November,China was hit by several cold events during the early winter of 2020/21.The lowest temperature observed at Beijing station on 7 January reached−19.6°C.In this paper,we show that the outbr... Starting in mid-November,China was hit by several cold events during the early winter of 2020/21.The lowest temperature observed at Beijing station on 7 January reached−19.6°C.In this paper,we show that the outbreak of the record-breaking extreme cold event can be attributed to a huge merging Ural blocking(UB)ridge over the Eurasian region.The sea-ice cover in the Kara and East Siberia Seas(KESS)in autumn was at its lowest value since 1979,which could have served as a precursor signal.Further analysis shows that several successive UB episodes occurred from 1 September 2020 to 10 January 2021.The persistent UB that occurred in late September/early October 2020 may have made an important contribution to the October historical minimum of sea ice in the KESS region.Our results also show that,after each UB episode in winter,significant upward propagation of wave activity occurred around 60°E,which resulted in weakening the stratospheric vortex.Meanwhile,each UB episode also caused a significant reduction in sea-ice extent in KESS and a significant weakening of the westerly jet in mid-high-latitude Eurasia.Results suggest that the Arctic vortex,which is supposed to enhance seasonally,became weaker and more unstable than the climatic mean under the seasonal cumulative effects of UB episodes,KESS warming,and long-lasting negative-phase North Atlantic Oscillation(NAO-).Those seasonal cumulative effects,combined with the impact of La Niña winter,led to the frequent occurrence of extreme cold events. 展开更多
关键词 extreme cold events Ural blocking Arctic sea ice Arctic vortex cumulative effect
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Analysis of cumulative handoff delay for graded secondary users in cognitive radio networks
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作者 Zhang Lei 张雷 +2 位作者 宋铁成 吴名 胡静 《Journal of Southeast University(English Edition)》 EI CAS 2013年第2期111-117,共7页
According to the fact that the secondary users' delay requirements for data transmission are not unitary in cognitive radio networks, the secondary users are divided into two classes, denoted by SU1 and SU2, respecti... According to the fact that the secondary users' delay requirements for data transmission are not unitary in cognitive radio networks, the secondary users are divided into two classes, denoted by SU1 and SU2, respectively. It is assumed that SU1 has a higher priority to occupy the primary users' unutilized channels than SU2. A preemptive resume priority M/G/1 queuing network is used to model the multiple spectrum handoffs processing. By using a state transition probability matrix and a cost matrix, the average cumulative delays of SU1 and SU2 are calculated, respectively. Numerical results show that the more the primary user's traffic load, the more rapidly the SU2's cumulative handoff delay grows. Compared with the networks where secondary users are unitary, the lower the SUI's arrival rate, the more obviously both SUI's and SU2's handoff delays decrease. The admission access regions limited by the maximum tolerable delay can also facilitate the design of admission control rules for graded secondary users. 展开更多
关键词 cognitive radio network graded secondary users multiple spectrum handoffs cumulative handoff delay admission access region
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Long-term follow-up of cumulative incidence of hepatocellular carcinoma in hepatitis B virus patients without antiviral therapy 被引量:6
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作者 Xiao-Yan Jiang Bing Huang +5 位作者 Dan-Ping Huang Chun-Shan Wei Wei-Chao Zhong De-Ti Peng Fu-Rong Huang Guang-Dong Tong 《World Journal of Gastroenterology》 SCIE CAS 2021年第11期1101-1116,共16页
BACKGROUND China has a high prevalence of hepatitis B virus(HBV),but most chronic hepatitis B(CHB)patients do not receive standardized antiviral therapy.There are few relevant reports addressing the outcomes of the la... BACKGROUND China has a high prevalence of hepatitis B virus(HBV),but most chronic hepatitis B(CHB)patients do not receive standardized antiviral therapy.There are few relevant reports addressing the outcomes of the large number of CHB patients who do not receive antiviral therapy.AIM To observe the outcomes of long-term follow-up of patients with CHB without antiviral treatment.METHODS This study included 362 patients with CHB and 96 with hepatitis B cirrhosis without antiviral treatment and with only liver protection and anti-inflammatory treatment from 1993 to 1998.The median follow-up times were 10 and 7 years,respectively.A total of 203 CHB and 129 hepatitis B cirrhosis patients receiving antiviral therapy were selected as the control groups.The median follow-up times were 8 and 7 years,respectively.Kaplan-Meier curves were used to analyze the cumulative incidence of hepatocellular carcinoma(HCC),and the Cox regression model was used to analyze the risk factors for HCC.RESULTS Among the patients in the non-antiviral group,16.9%had spontaneous decreases(HBeAg)seroconversion.In the antiviral group,87.2%of patients had undetectable HBV DNA,and 52%showed HBeAg seroconversion.Among CHB and hepatitis B cirrhosis patients,the cumulative incidence rates of HCC were 14.9%and 53.1%,respectively,in the non-antiviral group and were 10.7%and 31.9%,respectively,in the antiviral group.There was no difference between the two groups regarding the CHB patients(P=0.842),but there was a difference between the groups regarding the hepatitis B cirrhosis patients(P=0.026).The cumulative incidence rates of HCC were 1.6%and 22.3%(P=0.022)in the groups with and without spontaneous HBeAg seroconversion,respectively.The incidence rates of HCC among patients with and without spontaneous declines in HBV DNA to undetectable levels were 1.6%and 19.1%,respectively(P=0.051).There was no difference in the cumulative incidence of HCC between the two groups regarding the patients with drug-resistant CHB(P=0.119),but there was a significant difference between the two groups regarding the patients with cirrhosis(P=0.004).The Cox regression model was used for regression of the corrected REACH-B score,which showed that alanine aminotransferase>400 U/L,history of diabetes,and family history of liver cancer were risk factors for HCC among men aged>40 years(P<0.05).Multifactorial analysis showed that a family history of HCC among men was a risk factor for HCC.CONCLUSION Antiviral therapy and non-antiviral therapy with liver protection and antiinflammatory therapy can reduce the risk of HCC.Antiviral therapy may mask the spontaneous serological response of some patients during CHB.Therefore,the effect of early antiviral therapy on reducing the incidence of HCC cannot be overestimated. 展开更多
关键词 Chronic hepatitis B Anti-inflammatory therapy Hepatoprotective therapy cumulative incidence Hepatocellular carcinoma Antiviral therapy
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Research progress on permeability improvement mechanisms and technologies of coalbed deep-hole cumulative blasting 被引量:7
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作者 Deyong Guo Pengfei Lv +1 位作者 Jiechao Zhao Chao Zhang 《International Journal of Coal Science & Technology》 EI 2020年第2期329-336,共8页
Coalbed gas extraction is an important means of exploiting and utilizing gas resources,as well as a means of preventing coal mine disasters.In view of the low gas extraction rate from coalbeds with high gas content an... Coalbed gas extraction is an important means of exploiting and utilizing gas resources,as well as a means of preventing coal mine disasters.In view of the low gas extraction rate from coalbeds with high gas content and low permeability,a method of improving permeability through deep-hole cumulative blasting is applied to develop initial directional fractures using a jet flow.Under the action of the blasting stress wave and detonation gas wedge,the fractures extend over a large range within the coal,thereby improving coalbed permeability.This study focuses on the criteria of cumulative blasting-induced coalbed fracturing based on a literature review of the penetration effect of cumulative blasting.On this basis,we summarize the coal fracturing zone,crack extension process,and the key technologies of charging and hole sealing for cumulative blasting.In addition,the latest research progress in the optimization of field test drilling and blasting parameters for cumulative blasting is introduced.Research findings indicate that the permeability improvement mechanism of cumulative blasting could be further enhanced,and the technology and technical equipment are in urgent need of improvement.Finally,development trends in the cumulative blasting permeability improvement technique are identified. 展开更多
关键词 cumulative blasting Fracturing mechanism Coalbed permeability improvement Permeability improvement technology Gas extraction
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Enhancement effect of cumulative second-harmonic generation by closed propagation feature of circumferential guided waves 被引量:1
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作者 Guang-Jian Gao Ming-Xi Deng +1 位作者 Ning Hu Yan-Xun Xiang 《Chinese Physics B》 SCIE EI CAS CSCD 2020年第2期301-308,共8页
On the basis of second-order perturbation approximate and modal expansion approach,we investigate the enhancement effect of cumulative second-harmonic generation(SHG)of circumferential guided waves(CGWs)in a circular ... On the basis of second-order perturbation approximate and modal expansion approach,we investigate the enhancement effect of cumulative second-harmonic generation(SHG)of circumferential guided waves(CGWs)in a circular tube,which is inherently induced by the closed propagation feature of CGWs.An appropriate mode pair of primary-and double-frequency CGWs satisfying the phase velocity matching and nonzero energy flux is selected to ensure that the second harmonic generated by primary CGW propagation can accumulate along the circumference.Using a coherent superposition of multi-waves,a model of unidirectional CGW propagation is established for analyzing the enhancement effect of cumulative SHG of primary CGW mode selected.The theoretical analyses and numerical simulations performed directly demonstrate that the second harmonic generated does have a cumulative effect along the circumferential direction and the closed propagation feature of CGWs does enhance the magnitude of cumulative second harmonic generated.Potential applications of the enhancement effect of cumulative SHG of CGWs are considered and discussed.The theoretical analysis and numerical simulation perspective presented here yield an insight previously unavailable into the physical mechanism of the enhancement effect of cumulative SHG by closed propagation feature of CGWs in a circular tube. 展开更多
关键词 CIRCUMFERENTIAL guided wave second-harmonic generation(SHG) enhancement effect of cumulative SHG CLOSED PROPAGATION FEATURE
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