This study describes the floristic composition and structure of a woody stand in the Senegalese Sahel, paying particular attention to the edaphic factors of its floristic composition. A stratified inventory considerin...This study describes the floristic composition and structure of a woody stand in the Senegalese Sahel, paying particular attention to the edaphic factors of its floristic composition. A stratified inventory considering the different relief units was adopted. Woody vegetation was surveyed using a dendrometric approach. The results obtained show that the flora is dominated by a few species adapted to drought, such as Balanites aegyptiaca (L.) Del., Calotropis procera Ait. and Boscia senegalensis (Pers.). The distribution of this flora and the structure of the ligneous plants are linked to the topography. In the lowlands, the flora is more diversified and the ligneous plants reach their optimum level of development compared with the higher relief areas. In the lowlands, there are a few woody species which, in the past, were indicative of better climatic conditions. These are Anogeissus leiocarpus (DC.), Commiphora africana (A. Rich.), Feretia apodanthera Del., Loeseneriella africana (A. Smith), Mitragyna inermis (Willd.) and Sclerocarya birrea (A. Rich). It is important that their reintroduction into reforestation projects takes account of their edaphic preference.展开更多
As an extended period of unusually dry weather conditions without sufficient rain, drought poses enormous risk on societies. Characterized by the absence of precipitation for long periods of time, often resulting in w...As an extended period of unusually dry weather conditions without sufficient rain, drought poses enormous risk on societies. Characterized by the absence of precipitation for long periods of time, often resulting in water scarcity, droughts are increasingly posing significant environmental challenges. Drought is therefore considered an important element in the management of water resources, especially groundwater resources during drought. This study therefore sought to investigate the rainfall variability and the frequency of drought for the period 1991 to 2020 in Bamako based on monthly rainfall data from Bamako-Senou gauge station. The standardized precipitation index (SPI) for 12-month, 6-month and 3-month timescales and the SPI for annual totals were used to characterized drought in the study area (Bamako). Univariate parametric probability distributions such as Normal, Log-normal, Gumbel type I and Pearson type III (P3) distributions were fitted with drought variables (severity and duration) for future planning and management. Non-parametric test such as Mann-Kendall trend test was also used to detect trend in annual rainfall data. The results showed that based on 12-month SPI, Bamako experienced two (02) extreme droughts one in July 2002 (SPI = -2.2165) and another in June 2015 (SPI = -2.0598 QUOTE SPI=-2.0598 ). Drought years represented 46.67% for the overall periods according to the SPI for annual totals. The result further indicated that based on the goodness of fit test, the P3 distribution represents the best fitted distribution to both drought severity and duration over Bamako. Bamako is expected to experience several severe severities with higher and shorter duration in the future. Severities with 1, 2, 6, and 10-month duration had return periods ranged from 2.4 to 3.8 years, while 5, 10, 20, 25, 50, and 100-year return periods had 18.51, 26.08, 33.25, 35.50, 42.38, and 49.14 severities, respectively, and durations associated to these severities were 19.8, 26.9, 33.5, 35.6, 42, and 48.2 months, respectively.展开更多
Leaf area index (LAI) of natural vegetation is recognized as the most important variable for measuring vegetation structure over large areas, and for relating it to energy and mass exchange, which has been successfull...Leaf area index (LAI) of natural vegetation is recognized as the most important variable for measuring vegetation structure over large areas, and for relating it to energy and mass exchange, which has been successfully estimated from satellite resolution sensors. In this paper, according to the statistical analysis based on a lot of forest plots, the mathematical models of LAI distribution patterns in the hydro thermal spaces for five coniferous forest types in China were established. For the cold temperate larch forests growing in the dry and cold climate, their LAI increases with the increasing of warm index and precipitation in the way of hyperbolic quadratic surface. For the cold temperate spruce fir forests and temperate Pinus tabulaeformis forests, their LAI is negatively related to the annual mean air temperature in the way of the natural exponential curve, in order to adapt to the water oppressed environments. For the subtropical Pinus massoniana forests and Cunninghamia lanceolata forests growing in the warm and moist climate, their LAI is related to the annual mean air temperature in the way of the parabolic quadratic curve.展开更多
Genetic,lifestyle,and environmental factors contribute to the etiology of polycystic ovary syndrome(PCOS).Increased body mass index(BMI)exacerbates the reproductive and metabolic parameters and reduces the fecundity o...Genetic,lifestyle,and environmental factors contribute to the etiology of polycystic ovary syndrome(PCOS).Increased body mass index(BMI)exacerbates the reproductive and metabolic parameters and reduces the fecundity of women with PCOS.This is a secondary analysis of a large-sample,multicenter,randomized controlled trial conducted at 21 sites in Chinese mainland.A total of 1000 women diagnosed with PCOS were enrolled in this trial.Of these,998 women with PCOS were included in the analysis.Increased BMI was associated with more severe menstrual irregularities,elevated testosterone level,higher prevalence of metabolic syndrome,and poorer quality of life.The rates of ovulation per woman for the normal,overweight,and obese BMI groups were 83.0%,78.2%,and 63.6%,respectively(P<0.001),and the rates of live birth were 23.6%,18.1%,and 15.3%(P=0.030).Northern PCOS patients showed more severe reproductive,glucose,and lipid profiles;less exercise;and lower total ovulation rates compared with PCOS patients from Southern China(74.8%vs 81.2%,absolute difference 6.4%,95%confidence interval 1.2%–11.5%).The results show the typical phenotypic features of Han women with PCOS in Northern and Southern China.The women living in Northern China showed a higher BMI,more severe glycolipid metabolism profiles,and subsequently worse clinical outcomes by the same interventions than those living in Southern China.The difference in phenotypic features can be explained mostly by differences in BMI and the resulting difference in ovulation.展开更多
In this paper the authors study the sample behavior of the Gini’s index of dissimilarity in the case of two samples of equal size drawn from the same uniform population. The paper present the analytical results obtai...In this paper the authors study the sample behavior of the Gini’s index of dissimilarity in the case of two samples of equal size drawn from the same uniform population. The paper present the analytical results obtained for the exact distribution of the index of dissimilarity for sample sizes n ≤ 8. This result was obtained by expressing the index of dissimilarity as a linear combination of spacings of the pooled sample. The obtained results allow to achieve the exact expressions of the moments for any sample size and, therefore, to highlight the main features of the sampling distributions of the index of dissimilarity. The present study can enhance inferential statistical aspects about one of the main contributions of Gini.展开更多
Body Mass Index (BMI), defined as the ratio of individual mass (in kilograms) to the square of the associated height (in meters), is one of the most widely discussed and utilized risk factors in medicine and public he...Body Mass Index (BMI), defined as the ratio of individual mass (in kilograms) to the square of the associated height (in meters), is one of the most widely discussed and utilized risk factors in medicine and public health, given the increasing obesity worldwide and its relation to metabolic disease. Statistically, BMI is a composite random variable, since human weight (converted to mass) and height are themselves random variables. Much effort over the years has gone into attempts to model or approximate the BMI distribution function. This paper derives the mathematically exact BMI probability density function (PDF), as well as the exact bivariate PDF for human weight and height. Taken together, weight and height are shown to be correlated bivariate lognormal variables whose marginal distributions are each lognormal in form. The mean and variance of each marginal distribution, together with the linear correlation coefficient of the two distributions, provide 5 nonadjustable parameters for a given population that uniquely determine the corresponding BMI distribution, which is also shown to be lognormal in form. The theoretical analysis is tested experimentally by gender against a large anthropometric data base, and found to predict with near perfection the profile of the empirical BMI distribution and, to great accuracy, individual statistics including mean, variance, skewness, kurtosis, and correlation. Beyond solving a longstanding statistical problem, the significance of these findings is that, with knowledge of the exact BMI distribution functions for diverse populations, medical and public health professionals can then make better informed statistical inferences regarding BMI and public health policies to reduce obesity.展开更多
This study investigated the impact of topography and vegetation on distribution of rare earth elements(REEs)in calcareous soils using methods of single extraction and mass balance calculation. The purposes of the stud...This study investigated the impact of topography and vegetation on distribution of rare earth elements(REEs)in calcareous soils using methods of single extraction and mass balance calculation. The purposes of the study were to set a basis for further research on the biogeochemical REE cycle and to provide references for soil–water conservation and REE-containing fertilizer amendments. The results show a generally flat Post-Archean Average Australian Shale—normalized REE pattern for the studied calcareous soils. REE enrichment varied widely. The proportion of acidsoluble phases of heavy REEs was higher than that of light REEs. From top to bottom of the studied hills, dominant REE sources transitioned from limestone in-situ weathering to input from REE-containing phases(e.g., clay minerals,amorphous iron, REE-containing fluids). Our results indicate that the REE content of calcareous soils is mainly controlled by slope aspect, while the enrichment degree of REEs is related to geomorphological position and vegetation type.Furthermore, the proportion of acid-soluble phases of REEs is mainly controlled by geomorphological position.展开更多
The angular distributions of sputtered Cd atoms were measured with 27 keV Ar+ ion bombardment at normal incidence for different target temperatures by using collector technique and RBS analysis. After the sputtering e...The angular distributions of sputtered Cd atoms were measured with 27 keV Ar+ ion bombardment at normal incidence for different target temperatures by using collector technique and RBS analysis. After the sputtering experiment the surface structures were observed using scanning electron microscope. For all samples the angular distributions are over-cosine. But the exponent n from fits of cosn θ to experimental angular distributions changes with target temperature. A simple model is proposed to explain the relation between shape of angular distribution and topography of sputtered surface.展开更多
City size distribution is of interest because of a number of key stylized facts, including notably Zipf's law for cities and the importance of urban primacy. But a new and more efficient method Gini index can be u...City size distribution is of interest because of a number of key stylized facts, including notably Zipf's law for cities and the importance of urban primacy. But a new and more efficient method Gini index can be used for calculating regional city size distribution. This paper begins by developing a calculation method for the Gini index, dividing the whole country into 26 areas and then calculating each area's Gini index value. Based on these calculation results, this paper gives a preliminary study on regional differences of its city size distribution and the dynamics.展开更多
The growth of wind energy penetration level in distribution system raises the concern about its impact on the operation of the power system, especially voltage stability and power loss. Among the major concerns, this ...The growth of wind energy penetration level in distribution system raises the concern about its impact on the operation of the power system, especially voltage stability and power loss. Among the major concerns, this paper studied the impact of connecting wind Turbine (WT) in radial distribution system with different penetration levels and different power factor (lead and lag) on power system voltage stability and power loss reduction. Load flow calculation was carried out using forward-backward sweep method. The analysis proceeds on 9- and 33-bus radial distribution systems. Results show that voltage stability enhancement and power loss reduction should be considered as WT installation objective.展开更多
Species distribution models have been widely used to explore suitable habitats of species,the impact of climate change on the distribution of suitable habitats of species,and the construction of ecological reserves.Th...Species distribution models have been widely used to explore suitable habitats of species,the impact of climate change on the distribution of suitable habitats of species,and the construction of ecological reserves.This paper introduced species distribution models commonly used in biodiversity analysis,as well as model performance evaluation indexes,challenges in the application of species distribution models,and finally prospected the development trend of research on species distribution models.展开更多
BACKGROUND Compared with patients with other causes of acute pancreatitis,those with hypertriglyceridemia-induced acute pancreatitis(HTG-AP)are more likely to develop persistent organ failure(POF).Therefore,recognizin...BACKGROUND Compared with patients with other causes of acute pancreatitis,those with hypertriglyceridemia-induced acute pancreatitis(HTG-AP)are more likely to develop persistent organ failure(POF).Therefore,recognizing the individuals at risk of developing POF early in the HTG-AP process is a vital for improving outcomes.Bedside index for severity in acute pancreatitis(BISAP),a simple parameter that is obtained 24 h after admission,is an ideal index to predict HTG-AP severity;however,the suboptimal sensitivity limits its clinical application.Hence,current clinical scoring systems and biochemical parameters are not sufficient for predicting HTG-AP severity.AIM To elucidate the early predictive value of red cell distribution width(RDW)for POF in HTG-AP.METHODS In total,102 patients with HTG-AP were retrospectively enrolled.Demographic and clinical data,including RDW,were collected from all patients on admission.RESULTS Based on the Revised Atlanta Classification,37(33%)of 102 patients with HTG-AP were diagnosed with POF.On admission,RDW was significantly higher in patients with HTG-AP and POF than in those without POF(14.4%vs 12.5%,P<0.001).The receiver operating characteristic curve demonstrated a good discrim-inative power of RDW for POF with a cutoff of 13.1%,where the area under the curve(AUC),sensitivity,and specificity were 0.85,82.4%,and 77.9%,respectively.When the RDW was≥13.1%and one point was added to the original BISAP to obtain a new BISAP score,we achieved a higher AUC,sensitivity,and specificity of 0.89,91.2%,and 67.6%,respectively.CONCLUSION RDW is a promising predictor of POF in patients with HTG-AP,and the addition of RDW can promote the sensitivity of BISAP.展开更多
In this paper, a polymer spherical symmetry GRIN sphere lens were prepared by the suspension-diffusion-copolymerization(SDC) technique, selecting methyl methacrylate(MMA) as monomer M1 and acrylic 2,2,2-trifluoroethyl...In this paper, a polymer spherical symmetry GRIN sphere lens were prepared by the suspension-diffusion-copolymerization(SDC) technique, selecting methyl methacrylate(MMA) as monomer M1 and acrylic 2,2,2-trifluoroethyl ester(3FEA) as M2. The radial distribution of refractive index of the lens was measured by the shearing interference method, which demonstrated that the quadratic refractive-index distribution was formed in the sphere lens, and its Δn=0.019.展开更多
文摘This study describes the floristic composition and structure of a woody stand in the Senegalese Sahel, paying particular attention to the edaphic factors of its floristic composition. A stratified inventory considering the different relief units was adopted. Woody vegetation was surveyed using a dendrometric approach. The results obtained show that the flora is dominated by a few species adapted to drought, such as Balanites aegyptiaca (L.) Del., Calotropis procera Ait. and Boscia senegalensis (Pers.). The distribution of this flora and the structure of the ligneous plants are linked to the topography. In the lowlands, the flora is more diversified and the ligneous plants reach their optimum level of development compared with the higher relief areas. In the lowlands, there are a few woody species which, in the past, were indicative of better climatic conditions. These are Anogeissus leiocarpus (DC.), Commiphora africana (A. Rich.), Feretia apodanthera Del., Loeseneriella africana (A. Smith), Mitragyna inermis (Willd.) and Sclerocarya birrea (A. Rich). It is important that their reintroduction into reforestation projects takes account of their edaphic preference.
文摘As an extended period of unusually dry weather conditions without sufficient rain, drought poses enormous risk on societies. Characterized by the absence of precipitation for long periods of time, often resulting in water scarcity, droughts are increasingly posing significant environmental challenges. Drought is therefore considered an important element in the management of water resources, especially groundwater resources during drought. This study therefore sought to investigate the rainfall variability and the frequency of drought for the period 1991 to 2020 in Bamako based on monthly rainfall data from Bamako-Senou gauge station. The standardized precipitation index (SPI) for 12-month, 6-month and 3-month timescales and the SPI for annual totals were used to characterized drought in the study area (Bamako). Univariate parametric probability distributions such as Normal, Log-normal, Gumbel type I and Pearson type III (P3) distributions were fitted with drought variables (severity and duration) for future planning and management. Non-parametric test such as Mann-Kendall trend test was also used to detect trend in annual rainfall data. The results showed that based on 12-month SPI, Bamako experienced two (02) extreme droughts one in July 2002 (SPI = -2.2165) and another in June 2015 (SPI = -2.0598 QUOTE SPI=-2.0598 ). Drought years represented 46.67% for the overall periods according to the SPI for annual totals. The result further indicated that based on the goodness of fit test, the P3 distribution represents the best fitted distribution to both drought severity and duration over Bamako. Bamako is expected to experience several severe severities with higher and shorter duration in the future. Severities with 1, 2, 6, and 10-month duration had return periods ranged from 2.4 to 3.8 years, while 5, 10, 20, 25, 50, and 100-year return periods had 18.51, 26.08, 33.25, 35.50, 42.38, and 49.14 severities, respectively, and durations associated to these severities were 19.8, 26.9, 33.5, 35.6, 42, and 48.2 months, respectively.
文摘Leaf area index (LAI) of natural vegetation is recognized as the most important variable for measuring vegetation structure over large areas, and for relating it to energy and mass exchange, which has been successfully estimated from satellite resolution sensors. In this paper, according to the statistical analysis based on a lot of forest plots, the mathematical models of LAI distribution patterns in the hydro thermal spaces for five coniferous forest types in China were established. For the cold temperate larch forests growing in the dry and cold climate, their LAI increases with the increasing of warm index and precipitation in the way of hyperbolic quadratic surface. For the cold temperate spruce fir forests and temperate Pinus tabulaeformis forests, their LAI is negatively related to the annual mean air temperature in the way of the natural exponential curve, in order to adapt to the water oppressed environments. For the subtropical Pinus massoniana forests and Cunninghamia lanceolata forests growing in the warm and moist climate, their LAI is related to the annual mean air temperature in the way of the parabolic quadratic curve.
基金This study was supported by National Public Welfare Projects for Chinese Medicine(201507001-02)the Heilongjiang Province General Institutes of Higher Education Youth Innovative Talents Program(UNPYSCT-2017226)the Scientific Research Project of Outstanding Innovative Talents Program of Heilongjiang University of Chinese Medicine(2018RC012),Xuzhou Clinical Medical Team Talent Introduction Project—Academician Liu Yixun Integrated Chinese and Western medicine,Maternity and Reproductive Technology Innovation Team,and Academician Liu Yixun Workstation Project.
文摘Genetic,lifestyle,and environmental factors contribute to the etiology of polycystic ovary syndrome(PCOS).Increased body mass index(BMI)exacerbates the reproductive and metabolic parameters and reduces the fecundity of women with PCOS.This is a secondary analysis of a large-sample,multicenter,randomized controlled trial conducted at 21 sites in Chinese mainland.A total of 1000 women diagnosed with PCOS were enrolled in this trial.Of these,998 women with PCOS were included in the analysis.Increased BMI was associated with more severe menstrual irregularities,elevated testosterone level,higher prevalence of metabolic syndrome,and poorer quality of life.The rates of ovulation per woman for the normal,overweight,and obese BMI groups were 83.0%,78.2%,and 63.6%,respectively(P<0.001),and the rates of live birth were 23.6%,18.1%,and 15.3%(P=0.030).Northern PCOS patients showed more severe reproductive,glucose,and lipid profiles;less exercise;and lower total ovulation rates compared with PCOS patients from Southern China(74.8%vs 81.2%,absolute difference 6.4%,95%confidence interval 1.2%–11.5%).The results show the typical phenotypic features of Han women with PCOS in Northern and Southern China.The women living in Northern China showed a higher BMI,more severe glycolipid metabolism profiles,and subsequently worse clinical outcomes by the same interventions than those living in Southern China.The difference in phenotypic features can be explained mostly by differences in BMI and the resulting difference in ovulation.
文摘In this paper the authors study the sample behavior of the Gini’s index of dissimilarity in the case of two samples of equal size drawn from the same uniform population. The paper present the analytical results obtained for the exact distribution of the index of dissimilarity for sample sizes n ≤ 8. This result was obtained by expressing the index of dissimilarity as a linear combination of spacings of the pooled sample. The obtained results allow to achieve the exact expressions of the moments for any sample size and, therefore, to highlight the main features of the sampling distributions of the index of dissimilarity. The present study can enhance inferential statistical aspects about one of the main contributions of Gini.
文摘Body Mass Index (BMI), defined as the ratio of individual mass (in kilograms) to the square of the associated height (in meters), is one of the most widely discussed and utilized risk factors in medicine and public health, given the increasing obesity worldwide and its relation to metabolic disease. Statistically, BMI is a composite random variable, since human weight (converted to mass) and height are themselves random variables. Much effort over the years has gone into attempts to model or approximate the BMI distribution function. This paper derives the mathematically exact BMI probability density function (PDF), as well as the exact bivariate PDF for human weight and height. Taken together, weight and height are shown to be correlated bivariate lognormal variables whose marginal distributions are each lognormal in form. The mean and variance of each marginal distribution, together with the linear correlation coefficient of the two distributions, provide 5 nonadjustable parameters for a given population that uniquely determine the corresponding BMI distribution, which is also shown to be lognormal in form. The theoretical analysis is tested experimentally by gender against a large anthropometric data base, and found to predict with near perfection the profile of the empirical BMI distribution and, to great accuracy, individual statistics including mean, variance, skewness, kurtosis, and correlation. Beyond solving a longstanding statistical problem, the significance of these findings is that, with knowledge of the exact BMI distribution functions for diverse populations, medical and public health professionals can then make better informed statistical inferences regarding BMI and public health policies to reduce obesity.
基金supported jointly by the National Natural Science Foundation of China(41571130042,41522207,41325010)the State’s Key Project of Research and Development Plan of China(2016YFA0601002)
文摘This study investigated the impact of topography and vegetation on distribution of rare earth elements(REEs)in calcareous soils using methods of single extraction and mass balance calculation. The purposes of the study were to set a basis for further research on the biogeochemical REE cycle and to provide references for soil–water conservation and REE-containing fertilizer amendments. The results show a generally flat Post-Archean Average Australian Shale—normalized REE pattern for the studied calcareous soils. REE enrichment varied widely. The proportion of acidsoluble phases of heavy REEs was higher than that of light REEs. From top to bottom of the studied hills, dominant REE sources transitioned from limestone in-situ weathering to input from REE-containing phases(e.g., clay minerals,amorphous iron, REE-containing fluids). Our results indicate that the REE content of calcareous soils is mainly controlled by slope aspect, while the enrichment degree of REEs is related to geomorphological position and vegetation type.Furthermore, the proportion of acid-soluble phases of REEs is mainly controlled by geomorphological position.
基金The Project Supported by National Natural Science Foundation of China
文摘The angular distributions of sputtered Cd atoms were measured with 27 keV Ar+ ion bombardment at normal incidence for different target temperatures by using collector technique and RBS analysis. After the sputtering experiment the surface structures were observed using scanning electron microscope. For all samples the angular distributions are over-cosine. But the exponent n from fits of cosn θ to experimental angular distributions changes with target temperature. A simple model is proposed to explain the relation between shape of angular distribution and topography of sputtered surface.
文摘City size distribution is of interest because of a number of key stylized facts, including notably Zipf's law for cities and the importance of urban primacy. But a new and more efficient method Gini index can be used for calculating regional city size distribution. This paper begins by developing a calculation method for the Gini index, dividing the whole country into 26 areas and then calculating each area's Gini index value. Based on these calculation results, this paper gives a preliminary study on regional differences of its city size distribution and the dynamics.
文摘The growth of wind energy penetration level in distribution system raises the concern about its impact on the operation of the power system, especially voltage stability and power loss. Among the major concerns, this paper studied the impact of connecting wind Turbine (WT) in radial distribution system with different penetration levels and different power factor (lead and lag) on power system voltage stability and power loss reduction. Load flow calculation was carried out using forward-backward sweep method. The analysis proceeds on 9- and 33-bus radial distribution systems. Results show that voltage stability enhancement and power loss reduction should be considered as WT installation objective.
基金Supported by Natural Science Foundation of Hunan Province (2021JJ30375)Natural Science Foundation of Hunan Provincial Department of Education (20A275)Science and Technology Innovation Team Project of Hunan Province (201937924).
文摘Species distribution models have been widely used to explore suitable habitats of species,the impact of climate change on the distribution of suitable habitats of species,and the construction of ecological reserves.This paper introduced species distribution models commonly used in biodiversity analysis,as well as model performance evaluation indexes,challenges in the application of species distribution models,and finally prospected the development trend of research on species distribution models.
基金the Science and Technology Program of Guiyang Baiyun District Science and Technology Bureau.No.[2017]50Science and Technology Program of Guiyang Municipal Bureau of Science and Technology,No.[2018]1-72Science and Technology Fund Project of Guizhou Provincial Health Commission,No.gzwkj2021-127.
文摘BACKGROUND Compared with patients with other causes of acute pancreatitis,those with hypertriglyceridemia-induced acute pancreatitis(HTG-AP)are more likely to develop persistent organ failure(POF).Therefore,recognizing the individuals at risk of developing POF early in the HTG-AP process is a vital for improving outcomes.Bedside index for severity in acute pancreatitis(BISAP),a simple parameter that is obtained 24 h after admission,is an ideal index to predict HTG-AP severity;however,the suboptimal sensitivity limits its clinical application.Hence,current clinical scoring systems and biochemical parameters are not sufficient for predicting HTG-AP severity.AIM To elucidate the early predictive value of red cell distribution width(RDW)for POF in HTG-AP.METHODS In total,102 patients with HTG-AP were retrospectively enrolled.Demographic and clinical data,including RDW,were collected from all patients on admission.RESULTS Based on the Revised Atlanta Classification,37(33%)of 102 patients with HTG-AP were diagnosed with POF.On admission,RDW was significantly higher in patients with HTG-AP and POF than in those without POF(14.4%vs 12.5%,P<0.001).The receiver operating characteristic curve demonstrated a good discrim-inative power of RDW for POF with a cutoff of 13.1%,where the area under the curve(AUC),sensitivity,and specificity were 0.85,82.4%,and 77.9%,respectively.When the RDW was≥13.1%and one point was added to the original BISAP to obtain a new BISAP score,we achieved a higher AUC,sensitivity,and specificity of 0.89,91.2%,and 67.6%,respectively.CONCLUSION RDW is a promising predictor of POF in patients with HTG-AP,and the addition of RDW can promote the sensitivity of BISAP.
文摘In this paper, a polymer spherical symmetry GRIN sphere lens were prepared by the suspension-diffusion-copolymerization(SDC) technique, selecting methyl methacrylate(MMA) as monomer M1 and acrylic 2,2,2-trifluoroethyl ester(3FEA) as M2. The radial distribution of refractive index of the lens was measured by the shearing interference method, which demonstrated that the quadratic refractive-index distribution was formed in the sphere lens, and its Δn=0.019.
文摘目的研究术前血小板分布宽度(Platelet volume distribution width,PDW)联合系统性炎症指数(Systemic inflammation response index,SIRI)对结肠癌术后复发转移的预测价值。方法以2020年1月-2021年6月江苏大学附属医院胃肠外科就诊并接受根治性切除手术治疗的194例结肠癌患者为结肠癌组,选择同期在本院体检中心招募的100例健康体检者为对照组。术前检测并记录PDW和SIRI,收集患者的一般资料包括:性别、年龄、身高、体重、家族肿瘤史、是否吸烟、酗酒、体质指数(Body mass index,BMI)、肿瘤最大径、TNM分期(Tumor node metastasis,TNM)和分化程度。对患者随访2年,记录结肠癌复发转移情况。采用ROC曲线确定相关变量的临界最佳值,通过AUC(ROC曲线下面积)评价其预后的准确性。结果与对照组比较,结肠癌组PDW和SIRI均显著增高,差异有统计学意义(P<0.05)。术后发生复发转移患者术前PDW与SIRI高于术后未发生复发转移的患者,差异有统计学意义(P<0.05)。TNM分期Ⅲ~Ⅳ期和中低分化程度术后复发转移患者的PDW高于Ⅰ~Ⅱ期患者和高分化程度患者,差异有统计学意义(P<0.05)。肿瘤最大径≥5 cm、TNM分期Ⅲ~Ⅳ期和中低分化程度术后复发转移患者的PDW高于肿瘤最大径<5 cm、TNM分期Ⅰ~Ⅱ期和高分化程度的患者,差异有统计学意义(P<0.05)。PDW、SIRI及两者联合预测结肠癌术后复发转移的曲线下面积(Area under curve,AUC)分别为0.761(95%CI:0.691~0.831),0.836(95%CI:0.775~0.897)和0.918(95%CI:0.876~0.960)。术后复发转移患者的PDW与SIRI呈显著正相关关系(r=0.574,P=0.003)。结论PDW、SIRI与结肠癌患者临床病理特征和术后复发转移有关,两者联合预测术后复发转移的效能较好,可为临床应用提供一定参考价值。
