Unitary Linear Regression Research Articles

Expression level of neutrophil extracellular traps in peripheral blood of patients with chronic heart failure complicated with venous thrombosis and its clinical significance

ObjectivePrevious studies have reported that neutrophil extracellular traps (NETs) have been identified to be involved in thrombosis, but the clinical value in chronic heart failure (CHF) patients with venous thrombosis is unclear. This study focused on the expression level of NETs in the peripheral blood of patients with CHF complicated with venous thrombosis and its clinical value.Methods80 patients with CHF were included and divided into 2 groups according to the occurrence of venous thrombosis, and the expression levels of NETs in peripheral venous blood and lesion veins of the patients were detected through fluorescent staining. Myeloperoxidase-DNA (MPO-DNA) and citrullinated histone H3 (CitH3), markers of NETs, were detected by enzyme linked immunosorbent assay kit. The receiver operating characteristic (ROC) curve was used to analyze the value of peripheral venous blood NETs in the diagnosis of venous thrombosis in CHF patients, while the relationship between NETs in peripheral and lesion veins was analyzed by a unitary linear regression model.ResultsThe results showed that the concentration of NETs, MPO-DNA, and CitH3 in CHF patients combined with venous thrombosis was markedly higher than that in patients without venous thrombosis, and the concentration of NETs, MPO-DNA, and CitH3 in lesion venous blood was notably higher than that in peripheral venous blood. Binary logistics regression analysis showed that NETs in peripheral venous blood were an independent risk factor for venous thrombosis in patients with heart failure. The unitary linear regression model fitted well, indicating a notable positive correlation between NETs concentrations in peripheral and lesion veins. The area under the ROC curve for diagnosing venous thrombosis was 0.85, indicating that peripheral blood NETs concentration levels could effectively predict venous thrombosis in CHF patients.ConclusionThe expression level of NETs was high in the peripheral blood of CHF patients combined with venous thrombosis and was the highest in lesion venous blood. NETs levels in peripheral blood had the value of diagnosing venous thrombosis in CHF patients, and the concentrations of NETs in peripheral and lesion veins are markedly positively correlated.

Quantitative analysis of chlorophyll in Catalpa bungei leaves based on partial least squares regression and spectral reflectance index

The photosynthetic pigment content of forest tree leaves is an important factor affecting photosynthesis in forest trees, and the non-destructive measurement of photosynthetic pigment content is particularly important in current research. The aim of this study was to develop a reflectance index for the determination of photosynthetic pigment content of Catalpa bungei leaves, and in addition to construct a model that can more accurately invert the photosynthetic pigment content. The correlation coefficient method was used to select influential reflectance indices for unitary linear regression model construction; and PLSR was used to accurately describe the photosynthetic pigment content of Catalpa bungei leaves using hyperspectral reflectance and its derived data as input variables. The results showed that the RPD values of Chla and Chl constructed by SR and ND were greater than 2.0, and the RPD value of Chlb was close to 2.0, and the RPD value of Chl/Car was greater than 1.4, and the RPD value of Chla/Chlb was less than 1.4. RLR as a factor to describe the ability of photosynthetic pigment ratio is relatively better than other input variables, Chla concentration and Chlb concentration real inversion to FDRL obviously optimal as input variables, R as the input variables to describe the ability of photosynthetic pigment is relatively better than other input variables. This study constructed an accurate and simplified model for the content of photosynthetic pigments in the leaves of Catalpa bungei, providing technical support for the development of low-cost instruments and the intrinsic correlation between photosynthetic pigments and reflectance.

Is the Stock Market a Reliable Indicator of the National Economy? -- Empirical Analysis According to Chinese Data

Based on Chinas economic data from 1992 to 2021, this essay employs the unitary linear regression model to investigate the effect of the Shanghai Composite Index on per capita GDP and carries out heterogeneity analysis from the perspective of different bank types. This paper concludes that the stock market in China has the function of a barometer. Based on different industries, the Chinese stock markets capacity as a barometer is effective in different industries, but Chinas stock market has the greatest effect on the tertiary industry, the second industry, and the least effect on the primary industry. Based on the expenditure approach, Chinese stock markets use as a barometer is effective for different components of GDP, but the effect of Chinas stock market on net exports of products and services is the largest, followed by government consumption and input-output ratio, and the effect on household consumption is the least. Based on the consideration of timing, the Chinese stock markets ability to serve as a barometer only took effect before the outbreak of the substandard goods crisis in 2008 and failed after the outbreak of the crisis.

Analysis of Supply–Demand Relationship of Cooling Capacity of Blue–Green Landscape under the Direction of Mitigating Urban Heat Island

Urban blue–green landscapes (UBGLs) have an important impact on the mitigation of UHIs. Clarifying the supply/demand relationship of the UBGLs’ cooling effect can serve as an indicator for high-quality urban development. We established the cooling capacity supply–demand evaluation systems of UBGLs by using multi-source data and a suitable landscape mesh size. Furthermore, we utilized the coupling coordination degree (CCD) model and the linear regression equation method to explore the spatial distribution of and variation in UBGLs’ cooling efficiency. The results showed the following: (1) according to the UBGL/SUHI landscape pattern index and the Pearson correlation coefficient of the land surface temperature (LST), the optimal mesh size was found to be 1200 m. (2) According to the unitary linear regression calculation, the matching of the cooling capacity supply and demand in the context of Qunli New Town showed obvious polarization; furthermore, Hanan new town and old town are more balanced than Qunli new town. (3) According to the spatiotemporal dynamic evolution of CCD, the proportion of moderate coordination- advancing cooling efficiency is the highest, reaching 35.3%. Second are moderate imbalance–hysteretic cooling efficiency (18.4%) and moderate imbalance–systematic balanced development (13.7%), with the old city highly coordinated area as the center and the coupling coordination type (gradually outward) turning into a state of serious imbalance, and then back into a state of high coordination. The findings of the investigations enriched a new viewpoint and practical scientific basis for UBGL system planning and cooling efficiency equity realizations.

Analysis of economic growth forecast based on regression model

In this paper, the population growth retardation model, the unitary linear regression model and the multiple linear regression model are established to solve the problem. After considering the year and population relationship, the total population and the future labor population are predicted by the growth retardation model, and the future education investment and the investment in fixed assets of the whole society are predicted by the unitary linear regression model. After considering such factors as education investment, total population, labor force population, and investment in fixed assets of the whole society, establish a linear relationship between the economy and these factors, and then solve the change of GDP under the joint influence of these factors through multiple regression analysis, and then predict that the economic growth rate in the next 20 years will be 4.71%, 4.49%, 4.29%, 4.10%, 3.93%, 3.78%, 3.64%, 3.51% 3.39%, 3.28%, 3.18%, 3.08%, 2.99% 2.91%, 2.83%, 2.75%, 2.68%, 2.61%, 2.55%, 2.48%. It can be seen that the future economic growth rate shows a downward trend. The growth rate of GDP per capita in the next 20 years will be 4.26%, 4.05%, 3.86%, 3.69%, 3.54%, 3.40%, 3.27%, 3.15%, 3.05%, 2.95%, 2.86%, 2.77%, 2.69%, 2.62%, 2.54%, 2.48%, 2.42%, 2.36%, 2.30%, 2.25%, showing a decreasing trend. Finally, it is concluded that the average annual growth rate of GDP per capita in the next 20 years will be 7%.

Combining UAV multispectral imagery and ecological factors to estimate leaf nitrogen and grain protein content of wheat

Nitrogen is an essential element of wheat growth and grain quality. Leaf nitrogen content (LNC), a critical monitoring indicator of crop nitrogen status, plays a reference role for later estimations of grain protein content (GPC). Developments in unmanned aerial vehicle (UAV) platforms and multispectral sensors have provided new approaches for LNC monitoring and GPC estimation, with great convenience for assessing the nutritional status of plants and grains without traditional destructive sampling. The objective of this study was to evaluate the feasibility of wheat LNC monitoring and GPC estimation based on UAV multispectral imagery. Wheat experiments were carried out in Xinghua, Kunshan and Suining of Jiangsu Province during 2018−2019 and in Rugao of Jiangsu Province during 2020−2021 with different varieties and nitrogen application rates. Remote sensing images were obtained by a multi-rotor UAV carrying a multispectral camera. The destructive sampling method was used to collect LNC, GPC and other field data. Wheat LNC monitoring and GPC estimation models were established after selection of the optimal indicators. Different modelling methods were used for the comparative analysis, including unitary linear regression, multiple linear regression and artificial neural network (ANN) methods. Three techniques were adopted to improve the GPC prediction accuracy: (1) multiple factors were substituted for single factor for the prediction; (2) texture information was added through further imagery mining; and (3) ecological factors were considered to improve the prediction mechanism. The results showed that the use of UAV-based Airphen multispectral imagery had a good effect on wheat LNC monitoring and GPC estimation. The vegetation indices constructed by red-edge and near-infrared bands had good performances in LNC monitoring and GPC estimation. The addition of texture information and ecological factors further improved the modelling accuracy. In this study, the optimal wheat GPC estimation model was established by NDVI (675, 730) at the jointing stage, NDVIT (730mea., 850) at the booting stage, NDVIT (730mea., 850) at the flowering stage and NDVI (730, 850) at the early filling stage. The modelling R2, validation R2 and relative root mean square error (RRMSE) reached 0.662, 0.7445 and 0.0635, respectively. The results provide a reference for crop LNC monitoring and GPC estimation based on UAV multispectral imagery.

Prediction Model of Microstructure and Properties of Al Foil Alloy During Thermal Deformation

Prediction model of microstructure and properties of Al foil alloy was established by thermo-simulation compression experiment. The relationships between grain size, material constants, and flow stress were studied. In thermal deformed Al foil alloy, the relationship between grain size and material parameter Z met an approximately linear relationship, and an unitary linear regression equation was established. The influence of grain size on flow stress during thermal deformation was highly significant. The prediction models could thus predict the structure of the alloy during thermal deformation effectively, and guide the Al foil rolling.

Vegetation Coverage Evaluation of Yangtze River Great Protection Based on Envi Software - A Case Study of Maanshan City

Now for the ecological protection is becoming more and more strict in China, in recent years also introduced many policies to strengthen vegetation protection of the Yangtze river region, vegetation coverage of the Yangtze river region has been the attention of people, has become a hot topic in the attention, now the rapid development of computer technology make the vegetation condition inspection of the Yangtze river region is becoming more and more obvious, vegetation index is a kind of effective indicators can monitor the vegetation and ecological environment, based on computer ENVI vegetation index data sets, can complete in time and space of common area of vegetation is analyzed, on the basis of this, Is applied to a yuan linear regression trend method to study the testing method of the non-normal distribution data of vegetation coverage of the Yangtze river triangular prism area is studied, the results of the study is also very effective, could detect the vegetation along the Yangtze river area in good time and space changes, found that the change of human activities on vegetation in the study also has the very big impact, and vegetation also made a positive response to human activities. On the whole, the vegetation coverage in the Yangtze River region presents a declining trend. Through the study and verification of the unitary linear regression equation, various vegetation conditions under the background of rapid urbanization are revealed, which provides reference and basis for the vegetation research in the Yangtze River region.

Spatiotemporal heterogeneity of PM2.5 and its relationship with urbanization in North China from 2000 to 2017

Fine particulate matter (PM2.5) pollution is becoming an increasing global concern due to rapid urbanization and socioeconomic development, especially in North China. Although North China experiences poor air quality and high PM2.5 concentrations, their spatial heterogeneity and relationship with the relative spatial risks of air pollution have not been explored. Therefore, in this study, the temporal variation trends (slope values) of the PM2.5 concentrations in North China from 2000 to 2017 were first quantified using the unitary linear regression model, and the Bayesian space-time hierarchy model was introduced to characterize their spatiotemporal heterogeneity. The spatial lag model was then used to examine the determinant power of urbanization and other socioeconomic factors. Additionally, the correlation between the spatial relative risks (probability of a region becoming more/less polluted relative to the average PM2.5 concentrations of the study area), and the temporal variation trends of the PM2.5 concentrations were quantified using the bivariate local indicators of spatial association model. The results showed that the PM2.5 concentrations increased during 2000–2017, and peaked in 2007 and 2013. Spatially, the cities at high risk of PM2.5 pollution were mainly clustered in southeastern Hebei, northern Henan, and western Shandong where the slope values were low, as demonstrated by the value of Moran's I (−0.56). Moreover, urbanization and road density were both positively correlated with PM2.5 pollution, while the proportion of tertiary industry was negatively correlated. Furthermore, a notable increasing trend was observed in some cities, such as Tianjin, Zaozhuang, Qingdao, and Xinyang. These findings can contribute to the development of effective policies from the perspective of rapid urbanization to relieve and reduce PM2.5 pollution.

Monitoring of Wheat Scab Using the Specific Spectral Index from ASD Hyperspectral Dataset

It is highly important to accurately monitor wheat scab and provide technical guidance for the crop pests and diseases. In this study, relevant analysis was performed among spectral reflectance, first-derivate data, and the disease severity data through ASD hyperspectral data. Two sensitive spectral wavelength ranges of 450–488 nm and 500–540 nm were selected. Then, a new wheat scab index (WSI) consisting of the two bands was proposed. The inversion models of the scab severities were comparatively built by unitary linear regression and multiple stepwise regression techniques. The results showed that the WSI had a significant linear relationship with severity of disease compared with other commonly used spectral indices. The fitting R2, testing R2, and RMSE were 0.73, 0.70, and 13.41, respectively. The multiple stepwise regression model established using the WSI, SDg/SDb, NBNDVI, and SDg as independent variables was better than the single-variable model. Our results suggest that WSI can be used to provide scientific guidance for monitoring and precise management of wheat scab disease.

The relationship of plasma fibrinogen with clinicopathological stages and tumor markers in patients with non-small cell lung cancer.

Numerous studies have shown that the blood of cancer patients are generally in hypercoagulable statement. The aim of the present research is to study the relationships of plasma fibrinogen (Fbg) levels with clinicopathological stages (CS) and tumor markers of non-small cell lung cancer (NSCLC).Baseline information, plasma Fbg levels, CS, and expression level of tumor markers were collected from medical records retrospectively. Unitary linear regression was used to analyze the relationships between continuous variables and Fbg, and multiple linear regression was used to analyze the relationships between categorical variables and Fbg. National Comprehensive Cancer Network Clinical Practice Guidelines in Oncology (Version 4) for NSCLC were adopted to evaluate CS.A total of 652 NSCLC patients were included. Compared with the females, male patients had higher mean plasma Fbg levels (P < .001). The later the N stages (P = .002), M stages (P = .002), and CS (P = .001) were, the higher the average plasma Fbg levels were. The levels of squamous cell carcinoma antigen (P = .001), carbohydrate antigen 125 (P = .041), and neuron-specific enolase (P < .001) were positively correlated with plasma Fbg concentration. The plasma level of Fbg in lung adenocarcinoma patients (P < .001) was the lowest, while that of lung squamous cell carcinoma patients (P < .001) was the highest in NSCLC patients.The plasma Fbg concentration is related to gender, CS, and tumor markers in patients with NSCLC.

Responses of vegetation growth to temperature during 1982-2015 in Xinjiang, China.

Combined with the normalized difference vegetation index (NDVI) dataset, vegetation type data, and meteorological data, we revealed the variation of vegetation growth responses to air temperature in the growing-season during 1982-2015 in Xinjiang, using the moving-windows based partial correlation analysis, the unitary linear regression analysis and GIS spatial analysis. Results showed that, in the whole growing-seasons of study period, there was a significant downturn trend in the responses of vegetation growth to temperature. At the seasonal scale, the downturn trend was obvious especially in summer and autumn, while it was in adverse in spring. During the whole gro-wing season, the responses of different vegetation types to air temperature change showed a decreasing trend. Seasonally, the responses of grassland and forest to temperature change showed a significant increase, while that of shrubland and desert were exactly the opposite in spring. The responses of all natural vegetation (grassland, shrubland, desert and forest) to temperature change showed a significant decreasing trend in summer, whereas their responses in autumn had no significant statistical characteristics. Spatially, the decreasing influence of temperature on the vegetation growth during the growing season in Xinjiang was universal, which might be due to the change in precipitation and solar radiation.

近10年湖北省植被指数时空变化特征及其驱动力

PDF HTML阅读 XML下载 导出引用 引用提醒 近10年湖北省植被指数时空变化特征及其驱动力 DOI: 10.5846/stxb201809011864 作者: 作者单位: 华中农业大学资源与环境学院,华中农业大学资源与环境学院;华中农业大学农业部长江中下游耕地保育重点实验室,华中农业大学资源与环境学院;华中农业大学农业部长江中下游耕地保育重点实验室,华中农业大学资源与环境学院;华中农业大学农业部长江中下游耕地保育重点实验室,华中农业大学资源与环境学院;华中农业大学农业部长江中下游耕地保育重点实验室 作者简介: 通讯作者: 中图分类号: 基金项目: 国家重点研发计划项目（2017YFC0505401）；国家自然资金基金项目（41877071）；中央高校基本科研业务费专项资助项目（2662016QD030） Analysis of spatial and temporal variations in vegetation index and its driving force in Hubei Province in the last 10 years Author: Affiliation: Department of Resoure and Environmental Information, College of Resources and Environment, Huazhong Agricultural University,Department of Resoure and Environmental Information, College of Resources and Environment, Huazhong Agricultural University; Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtze River) of the Ministry of Agriculture, Soil and Water Conservation Research Centre, Huazhong Agricultural University,Department of Resoure and Environmental Information, College of Resources and Environment, Huazhong Agricultural University; Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtze River) of the Ministry of Agriculture, Soil and Water Conservation Research Centre, Huazhong Agricultural University,, Fund Project: The National Key Research and Development Program of China [grant numbers 2017YFC0505401], the National Natural Science Foundation of China [grant numbers 41877071], the Fundamental Research Funds for the Central Universities Project of China [grant numbers 2662016QD030]. 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:为了明确湖北省植被长势变化特征及其影响因子，研究利用Landsat影像提取2005年、2010年以及2015年湖北省景观类型信息，分析近10年来景观时空变化特征；基于2005-2015年夏季MODIS/NDVI数据，采用一元线性回归、Theil-Sen median趋势、Mann-Kendall检验等分析方法对NDVI时空变化特征及其显著性进行探讨；采用最小二乘法对NDVI与气候之间的相关关系进行分析。使用DMSP/OLS和NPP/VIIRS夜间灯光数据探讨NDVI与人类经济活动之间的关系。结果表明：研究区景观类型变化以建设用地和耕地为主。耕地面积呈现逐年减少的趋势，主要转变为建设用地。建设用地面积不断增多，主要由耕地和林地转变而来，集中在武汉、荆州、襄阳城市圈；研究区NDVI值整体上表现为西高东低，以林地为主的十堰、恩施等地区NDVI值较高，以建设用地为主的武汉、襄阳、荆州等地区NDVI值较低；整体上NDVI变化呈轻微改善趋势，局部地区下降明显，鄂西北、鄂西南等地区NDVI稍有上升，武汉城市圈植被呈退化趋势；NDVI与降水量、气温的相关性均较弱，气候因子不是该区NDVI变化的主导因子；NDVI与夜间灯光亮度值呈显著负相关，相关系数达-0.8030，整体上人类经济活动与NDVI呈负相关关系，且有着分区性的特点，在武汉、襄阳等以建设用地为主的地区人类经济活动对NDVI起抑制作用，而在恩施、十堰等林地为主的地区人类活动对NDVI起促进作用。人类社会经济活动是影响研究区景观格局和植被变化的重要驱动力，城镇化扩张是湖北省植被变化的主要原因。 Abstract:To analyze the variation of vegetation growth and further explore the reasons for these changes in Hubei Province, we extracted landscape type information of Hubei Province in 2005, 2010, and 2015 using Landsat data, and analyzed the spatial and temporal evolution characteristic of landscape patterns. Based on the MODIS NDVI data in the summers of 2005 to 2015, the characteristics of spatial and temporal variation in NDVI and its significance were explored by using unitary linear regression analysis, Theil-Sen median trend analysis, and Mann-Kendall test. The relationship between NDVI and climatic factors (temperature and precipitation) was explored using the least squares method. The relationship between NDVI and human economic activities was also examined based on DMSP/OLS and NPP-VIIRS night-time light data. The results concluded that cultivated land and construction land were the landscape types that varied most in the study area between 2005 and 2015. The area of cultivated land continued to decline, and most of the area lost was transferred into construction land. The area of construction land continued to increase, and most of this increase was transferred from cultivated land and woodland, which were distributed in Wuhan City, Jingzhou City, and Xiangyang City. The NDVI value of the study area was generally high in the west and low in the east. The areas with higher NDVI values such as Shiyan and Enshi had woodland as the major landscape type. The areas with lower NDVI values such as Wuhan, Xiangyang, and Jingzhou, had construction land as the major landscape type. The overall variation of NDVI showed a slight improvement trend in Hubei Province. There was also an obvious declining trend for NDVI variation in some areas. The NDVI in the northwestern and western parts of Hubei Province increased slightly, and the vegetation in the Wuhan city showed a degrading trend. The correlation between NDVI and climatic factors (temperature and precipitation) was weak, which indicated that climatic factors are not the dominant factor causing NDVI variation. There was a significant negative correlation between NDVI and night-time light value, with a correlation coefficient of r=-0.8030. Overall, human economic activities were negatively correlated with NDVI, which also showed partitioning characteristics. Human economic activities have inhibited NDVI in areas where construction land is dominant such as Wuhan and Xiangyang, while NDVI is promoted in areas where woodland is dominant such as Enshi and Shiyan. Human economic activities were the key driving force for landscape pattern and vegetation variation in the study area. Urban expansion was the main reason for the spatial and temporal variations of vegetation in Hubei Province. 参考文献 相似文献 引证文献

Simple method for quick estimation of aquifer hydrogeological parameters

Development of simple and accurate methods to determine the aquifer hydrogeological parameters was of importance for groundwater resources assessment and management. Aiming at the present issue of estimating aquifer parameters based on some data of the unsteady pumping test, a fitting function of Theis well function was proposed using fitting optimization method and then a unitary linear regression equation was established. The aquifer parameters could be obtained by solving coefficients of the regression equation. The application of the proposed method was illustrated, using two published data sets. By the error statistics and analysis on the pumping drawdown, it showed that the method proposed in this paper yielded quick and accurate estimates of the aquifer parameters. The proposed method could reliably identify the aquifer parameters from long distance observed drawdowns and early drawdowns. It was hoped that the proposed method in this paper would be helpful for practicing hydrogeologists and hydrologists.

新疆托克逊观测气温的均一性分析与订正

采用托克逊国家一般气象观测站新、旧站址2015年1~12月同期气温观测资料,进行了对比分析。发现新、旧站的气温存在显著差异，新站与旧站平均气温、平均最高气温、平均最低气温存在显著性差异的月份占到78%，表明迁站导致托克逊站的观测气温出现了非均一性。初步分析表明，地理环境、下垫面性质、城区的热岛效应是造成气温出现显著差异的主要原因。用一元线性回归方法，把新站的气温资料订正到旧站，可以得到较准确的代表当地气温真实变化特点的均一性气温资料。 The corresponding air temperature data were contrastively analyzed between new and old ob-servation station at Toksun national general weather station. It was found that there was signifi-cance difference in air temperature between new and old station. 78 percent of months had sig-nificance difference in average, average maximum, average minimum air temperature between new and old station. Preliminary analysis showed that significance difference in air temperature resulted from the geographical environment, underlying surface properties and urban heat island effect. The air temperature data of new station were emended to old station by unitary linear regression analysis, which could get homogeneity air temperature data representing local air temperature change.

Joint associations of folate, homocysteine and MTHFR, MTR and MTRR gene polymorphisms with dyslipidemia in a Chinese hypertensive population: a cross-sectional study.

BackgroundDyslipidemia is a well-established risk factor for cardiovascular disease. Serum lipids were affected by several gene polymorphisms, folate, homocysteine and other metabolite levels. We aim to investigate the effects of homocysteine metabolism enzyme polymorphisms (MTHTR C677T, MTHFR A1298C, MTR A2756G and MTRR A66G) and their interactions with folate, homocysteine on serum lipid levels in Chinese patients with hypertension.MethodsParticipants were 480 hypertensive adults that enrolled in September to December 2005 from six different Chinese hospitals (Harbin, Shanghai, Shenyang, Beijing, Xi’an, and Nanjing). Known MTHFR C677T, MTHFR A1298C, MTR A2756G and MTRR A66G genotypes were determined by PCR-RFLP methods. Serum folate was measured by chemiluminescent immunoassay, homocysteine was measured by high-performance liquid chromatography, serum lipids parameters were determined by an automatic biochemistry analyzer, low-density lipoprotein was calculated by Friedewald’s equation. Unitary linear regression model was used to assess the associations of gene polymorphisms, folate and homocysteine on serum lipid profiles. Unconditional logistic regression model was applied to test the interactions of folate, homocysteine and gene polymorphisms on dyslipidemia.ResultsNo correlations between gene polymorphisms and homocysteine on serum lipid profiles. Compared with normal folate patients, patients with low folate showed higher odds of hypertriglyceridemia (OR = 2.02, 95 % CI: 1.25-3.25, P = 0.004) and low levels of high-density lipoprotein cholesterol (OR = 1.88, 95 % CI: 1.07-3.28, P = 0.027). Each of four gene polymorphisms (MTHTR C677T, MTHFR A1298C, MTR A2756G and MTRR A66G) combined with low folate showed higher odds of hypertriglyceridemia (P for trend: 0.049, 0.004, 0.007 and 0.005, respectively). MTHFR C677T and A1298C with low folate showed higher odds of low levels of high-density lipoprotein cholesterol (P for trend: 0.008 and 0.031).ConclusionsLow folate status and homocysteine metabolism gene polymorphisms (MTHTR C677T, MTHFR A1298C, MTR A2756G and MTRR A66G) may have a synergistic effect increased the incidence of dyslipidemia in Chinese hypertensive population.

Application value of optical coherence tomography in predicting visual outcome after vitrectomy for idiopathic macular epiretinal membrane

Background Idiopathic macular epiretinal membrane (IMEM) shows a high incidence and affects visual function of patients.The primary management of IMEM is vitrectomy, but the study on prediction of visual acuity after operation by optical coherence tomography (OCT) is seldom. Objective This study was to evaluate the predicting ability of OCT for preoperative visual outcome for IMEM patients who received vitrectomy. Methods The clinical data of IMEM patients with vitrectomy from March 2009 to May 2013 were retrospectively analyzed in People's Hospital Peking University.Forty-nine eyes of 48 cases were divided into continuous group (19 eyes of 18 cases) and discontinuous group (31 eyes of 31 cases) based on whether the extraretinal layers were intact on OCT, including retinal pigment epithelium (RPE), inner and outer segment of photoreceptors (IS/OS) and external limiting membrane (ELM).Central foveal thickness (CFT) by high-resolution spectral-domain OCT and best corrected visual acuity (BCVA) (LogMAR) before surgery and 12 weeks after surgery were recorded and compared between the two groups, and the correlations of shift of CFT with the shift of LogMAR vision was analyzed by unitary linear regression to evaluate the value of OCT in predicting postoperative vision.Writen informed consent was obtained from each patient prior to any medical operation.Written informed consent was obtained from each patient before surgery. Results In 12 weeks after operation, reflective strips of RPE layer, IS/OS and ELM layer were intact in 18 eyes of the continuous group after vitrectomy.The number of eyes with discontinuous strip in RPE layer decreased to 1 eye after operation from 6 eyes before operation, and the number of eyes with IS/OS reflective strip discontinue decreased to 19 eyes after operation from 29 eyes before operation, and that with ELM layer discontinue decreased to 15 eyes after operation from before operation in the discontinuous group.The improvement of LogMAR BCVA was increased with the decline of CFT values with a negative correlation between them (R2=0.298, B=0.001, P=0.000), and postoperative LogMAR visual acuity improved 1 line whenever CFT reduced by 100 μm.LogMAR BCVA was 0.4±0.19 before surgery and 0.36±0.21after surgery in the continuous group, showing a insignificant difference between them (t=0.876, P=0.393).In the discontinuous group, the postoperative logMAR BCVA was significantly higher after operation (0.46±0.26) than 0.82±0.41 after operation (t=6.206, P=0.000).The increase value of LogMAR after vitrectomy was 0.3 in the discontinuous group, which was superior to 0.0 of the continuous group. Conclusions The continuity of extraretinal layers and CFT by OCT are closely associated with the improvement of vision after vitrectomy in the eyes with IMEM. Postoperative vision is better in IMEM eye with continuous retinal reflective strips before operation, and majority of IMEM eyes can improve vision after operation. Preoperative OCT seems to be an important diagnostic tool for the selection of patients who benefit or not from surgery to certain extent. Key words: Computerized tomography; Optical coherence tomography; Visual outcome; Prognosis; Idiopathic macular epiretinal membranes; Vitrectomy

基于生态系统服务理论的中国绿色经济转型预测分析

In order to predict and analyze the way of China' s green transition,the calculation model on green economic indicators was put forward based on the theory of ecosystem services,the traditional input-output analysis method,the traditional environmental load model,decoupling theory and location quotient theory. These economic indicators can clearly show the dynamic relationship between resource consumption and environmental loss costs and ecosystem. By using simulation method the service values of all kinds of land ecosystems were firstly calculated in 2010 on the basis of the equivalent weights of land ecosystem service values in China. Moreover, the model on resource consumption and environmental loss costs was established based on service values of ecosystem. And these formulas for calculating green GDP,ecological load intensity,resource decoupling indicator and location quotient on green GDP were respectively presented. Using the above models and formulas the global and China's index values of green economy were calculated from2001 to 2010. With high development of the national economy in recent years, China' s resource consumption and environmental loss costs are increasing day by day. Many disputes and friction on the rights and responsibilities with the developed countries are also produced. On the basis of China' s future planning objectives on economic and social development as well as the relevant national statistical data,economic development indicators were calculated using theabove-mentioned models and the global future indicators were predicted using a unitary linear regression model. The predicted results showed that total cost of resource consumption and environmental loss would reach $ 3.11 × 1012 and net worth of green GDP per person reached $ 0. 37 × 104,the ecological load intensity,resource decoupling indicator and location quotient on green GDP were respectively 0.38,0.66 and 75 by 2015. The results in this study showed that China's ecological pressure would be gradually reduced,and the efficiency of resource utilization and location quotient on green GDP would be simultaneously improved with the economic benefit enhancing. The location quotient on green GDP will exceed the global average in 2020,the GDP per person will surpass ten thousand dollars and join the range of moderately developed countries in 2024. In future, China will still adhere to the principle of " common but differentiated responsibilities",and solve the disputes on the rights and responsibilities with other countries. Meanwhile,China will actively promote energy conservation,industrial restructuring,and further coordinate the regional relationship among economic development,natural resources and ecological environment.

More Efficient Methods among Commonly Used Robust Estimation Methods for Robust Unitary Linear Regression

Robust regression, based on the robust estimation, can effectively eliminate or weaken the influences of outliers. However, different robust methods have different abilities to eliminate or weaken the influences of outliers. The current paper employs simulation experiments, taking unitary linear regressions with different numbers of observations, different numbers of gross errors and different values of gross errors as examples, to compare the robustness of 13 commonly used robust estimation methods by the average values of relative gains. The results indicate that the L1 and GermanMcClure methods are relatively more efficient for unitary linear regression. They can more efficiently eliminate or weaken the influences of gross errors on regression coefficient valuation than other robust estimation methods.