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The Effect of Tuberculosis Infection on Pancreatic Beta-Cell Function in Patients with Type 2 Diabetes Mellitus
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作者 Mengdan Kong Ailin Zhong +1 位作者 Shilin Qu Junli Xue 《Advances in Bioscience and Biotechnology》 CAS 2024年第2期129-139,共11页
Objective: The aim of this study is to investigate how individuals with type 2 diabetes mellitus’ pancreatic β-cell function index and insulin resistance index are affected by tuberculosis infection. Methods: The st... Objective: The aim of this study is to investigate how individuals with type 2 diabetes mellitus’ pancreatic β-cell function index and insulin resistance index are affected by tuberculosis infection. Methods: The study group consisted of 89 patients with type 2 diabetes mellitus and tuberculosis infection who were admitted to Jingzhou Chest Hospital between March 2019 and March 2021. Gender and duration of diabetes were matching conditions. The control group was made up of 89 patients with type 2 diabetes who were admitted to Jingzhou Central Hospital’s endocrinology department during the same period. The two patient groups provided general information such as gender, age, length of diabetes, and blood biochemical indexes such as glycosylated hemoglobin (HbA1c), fasting glucose (FPG), and fasting C-peptide (FC-P). The HOMA calculator was used to calculate the HOMA-β and the HOMA-IR, and intergroup comparisons and correlation analyses were carried out. Results: Regarding gender, age, disease duration, FC-P, and HbA1c, the differences between the two groups were not statistically significant (P > 0.05). However, BMI, FPG, HOMA-β, and HOMA-IR showed statistically significant differences (P < 0.05). In comparison to the control group, the study group’s HOMA-β was lower and its HOMA-IR was greater. According to Spearman’s correlation analysis, HOMA-β had a negative association (P th FPG, HbA1c, and the length of the disease, and a positive correlation with BMI and FC-P. A positive correlation was found between HOMA-IR and BMI, FPG, and FC-P (P < 0.01), as well as a correlation with the length of the disease (P > 0.05) and HbA1c. Conclusions: In type 2 diabetes mellitus combined with tuberculosis infection, the patients had higher FPG levels and lower FC-P levels, the secretory function of pancreatic β-cells was more severely impaired, and insulin resistance was more obvious. 展开更多
关键词 Tuberculosis Infection Type 2 Diabetes Mellitus Pancreatic β-Cell function Insulin Resistance
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经颅磁声电刺激对健康与帕金森病大鼠神经回路中beta振荡的影响 被引量:1
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作者 张帅 由胜男 +2 位作者 杜文静 王磊 徐桂芝 《中国组织工程研究》 CAS 北大核心 2024年第16期2519-2526,共8页
背景:经颅磁声电刺激是一种基于磁声耦合电效应的无创、高精度脑神经聚焦刺激方法,可调节神经节律振荡活动,从而影响大脑的运动、认知等功能。目的:探究经颅磁声电刺激对健康与帕金森病大鼠神经回路中beta振荡的影响。方法:①动物实验:... 背景:经颅磁声电刺激是一种基于磁声耦合电效应的无创、高精度脑神经聚焦刺激方法,可调节神经节律振荡活动,从而影响大脑的运动、认知等功能。目的:探究经颅磁声电刺激对健康与帕金森病大鼠神经回路中beta振荡的影响。方法:①动物实验:采用随机数字表法将24只Wistar大鼠随机分为4组,每组6只:正常对照组不进行任何干预;正常刺激组大脑前额叶皮质接受经颅磁声电刺激(空间峰值脉冲平均强度为13.33 W/cm^(2),基波频率为0.4 MHz,基波周期数为1000,脉冲重复频率为200 Hz);模型对照组、模型刺激组通过腹腔注射1-甲基-4-苯基-1,2,3,6-四氢吡啶建立帕金森病模型,造模成功后,模型对照组大脑前额叶皮质接受经颅磁声电假刺激,模型刺激组大脑前额叶皮质接受经颅磁声电刺激,每天刺激时长2.0 min,刺激结束停留8-10 min后,采集大鼠执行T迷宫过程中局部场电位信号并同时记录行为学正确率,对比分析各组局部场电位信号能量的时频分布情况和行为差异,当大鼠正确率连续3 d高于80%后停止刺激实验和T迷宫实验。②建模仿真实验:构建经颅磁声电刺激下皮质-基底神经节回路模型,分别改变超声发射周期(5,10,20 ms)、超声发射占空比(30%,50%,90%)和感应电流密度(20,50,100μA/cm^(2)),比较不同刺激参数下健康与帕金森病大鼠beta振荡的功率谱密度值。结果与结论:①动物实验:正常对照组大鼠的空间学习能力强于模型对照组(P<0.001),正常刺激组大鼠的空间学习能力强于正常对照组(P<0.05),模型刺激组大鼠的空间学习能力强于模型对照组(P<0.01);正常对照组beta振荡能量分布较为集中,正常刺激组较正常对照组beta振荡信号能量有所降低,模型对照组与模型刺激组beta振荡能量广泛分布且能量值显著高于正常对照组、正常刺激组,并且模型刺激组beta振荡信号能量明显低于模型对照组;②建模仿真实验:不加刺激时,健康大鼠beta频段功率谱密度峰值(30 dB)显著低于帕金森病大鼠(55 dB);施加经颅磁声电刺激后,两组大鼠beta频段功率谱密度值普遍降低;beta频段功率谱密度峰值与超声发射周期呈正相关、与感应电流密度呈负相关,当超声发射占空比为50%时功率谱密度峰值最低;③结果表明:经颅磁声电刺激可抑制健康与帕金森病大鼠的beta振荡,进而改善大鼠的运动功能与决策认知功能。 展开更多
关键词 经颅磁声电刺激 皮质-基底神经节回路 beta振荡 帕金森病 局部场电位 T迷宫 神经调控
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高原鼠兔干扰对高寒草甸植物物种和功能性状beta多样性的影响
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作者 李捷 孙文涛 +3 位作者 庞晓攀 徐雪婷 杨欢 郭正刚 《生态学报》 CAS CSCD 北大核心 2024年第7期2993-3003,共11页
采用野外空间多点同步取样,分析了高原鼠兔干扰对高寒草甸植物物种beta多样性和植物功能性状beta多样性的影响,确定了高原鼠兔干扰下高寒草甸植物物种和功能性状beta多样性的变化途径,分别提出了高原鼠兔干扰区域内,基于植物物种多样性... 采用野外空间多点同步取样,分析了高原鼠兔干扰对高寒草甸植物物种beta多样性和植物功能性状beta多样性的影响,确定了高原鼠兔干扰下高寒草甸植物物种和功能性状beta多样性的变化途径,分别提出了高原鼠兔干扰区域内,基于植物物种多样性和功能性状多样性的高寒草甸植物多样性维持策略。结果表明,高原鼠兔干扰使高寒草甸植物物种相似性显著降低了28.1%,植物功能相似性降低了28.7%。尽管高原鼠兔干扰没有改变高寒草甸植物物种和功能性状beta多样性的变化途径,且对植物物种和功能性状的嵌套组分不存在显著影响,但高原鼠兔干扰显著降低了植物物种和功能性状周转组分所占的比例,降幅分别为36.6%和34.3%。高原鼠兔干扰区域内,高寒草甸植物物种beta多样性的变化以周转为主导(周转占比81.4%;嵌套占比:18.6%),植物功能性状beta多样性的变化以嵌套为主导(嵌套占比64.9%;周转占比35.1%)。因此,针对划定的高原鼠兔干扰区,需要同时保护区域内所有高原鼠兔栖息地(多位点保护),以达到维持植物物种多样性的目的,而可以仅通过保护该区域内植物功能性状丰富的位点,即可维持较高的植物功能多样性。 展开更多
关键词 高寒草甸 功能性状beta多样性 干扰 物种周转 主坐标分析
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草甸草原植物beta多样性高光谱遥感估算方法
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作者 杨星晨 雷少刚 +4 位作者 徐军 苏兆瑞 王维忠 宫传刚 赵义博 《光谱学与光谱分析》 SCIE EI CAS CSCD 北大核心 2024年第6期1751-1761,共11页
目前,全球生物多样性的状态非常堪忧,因此,利用光谱技术估算生物多样性成为了生态学家和遥感学家共同关注的热点。目前关于植物alpha多样性的研究很多,而关于beta多样性的研究较少,仍存在一些问题值得去探索。为了探究利用遥感技术估算... 目前,全球生物多样性的状态非常堪忧,因此,利用光谱技术估算生物多样性成为了生态学家和遥感学家共同关注的热点。目前关于植物alpha多样性的研究很多,而关于beta多样性的研究较少,仍存在一些问题值得去探索。为了探究利用遥感技术估算植物beta多样性的最佳光谱指数以及最佳影像空间分辨率,以草甸草原为研究区,基于无人机高光谱遥感影像,从光谱距离、光谱角度、生物多样性概念三个方面计算了6种beta多样性估算指数(4种为我们构建的新指数,2种为已有的指数),并采用Mantel tests和相关系数筛选最佳的光谱指数。然后将筛选出来的指数应用于不同空间分辨率的影像,以期得到最佳观测尺度。另外,为了提高指数的估算能力,对比了一阶导数变换和Savitzky-Golay滤波两种光谱变换方法,以及相关系数法、连续投影法、竞争性自适应重加权法三种特征波段选择方法。结果表明,不论是采用亚尺度观测(像元大小<样方大小)还是等尺度观测(像元大小=样方大小),最佳的光谱指数均为光谱距离指数,且光谱距离指数在不同影像空间分辨率下均表现良好。在草原地区,当影像空间分辨率约为0.25 m时,该指数可以取得最佳的估算结果。经一阶导数变换并用相关系数法提取特征波段后构建的光谱距离指数与beta多样性拥有最强的相关性,今后可利用该指数构建估算模型或者直接表征beta多样性。该研究对于科学的选取光谱指数和影像空间分辨率去估算植物beta多样性具有一定的指导意义。 展开更多
关键词 beta多样性 高光谱遥感 光谱指数 观测尺度 光谱曲线
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晶种辅助蒸气转化Al-SBA-15合成Beta纳米晶团聚体
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作者 孙琳 林森 王润伟 《高等学校化学学报》 SCIE EI CAS CSCD 北大核心 2024年第8期35-42,共8页
采用晶种辅助蒸气转化(SASC)策略,将有序介孔分子筛Al-SBA-15颗粒直接转化为Beta纳米晶团聚体(BNA).除规则微孔外,BNA含有2种多级介孔结构.研究了骨架组装与多级孔结构的关系.通过调节热分解条件,将P123胶束选择性分解成碳颗粒并分散于A... 采用晶种辅助蒸气转化(SASC)策略,将有序介孔分子筛Al-SBA-15颗粒直接转化为Beta纳米晶团聚体(BNA).除规则微孔外,BNA含有2种多级介孔结构.研究了骨架组装与多级孔结构的关系.通过调节热分解条件,将P123胶束选择性分解成碳颗粒并分散于Al-SBA-15介孔中,在颗粒内部构建了均匀的三维纳米空间网格.通过浸渍Beta晶种和四乙基铵阳离子(TEA+)强化分子筛成核,采用蒸气处理方法,将Al-SBA-15无定形孔壁在纳米空间中缓慢转化为Beta纳米晶体.通过调节合成参数,使纳米晶体沿Al-SBA-15孔壁方向规则排列,形成有序介观结构.此外,经高温焙烧去除碳颗粒后,BNA内部生成了穴状介孔.实验结果表明,低的溶剂用量可显著降低传质速度,提高骨架组装质量,从而使BNA酸性增强.优异的多级孔结构和较强的酸性使BNA在大分子反应中具有应用潜力. 展开更多
关键词 多级孔beta纳米晶 Al-SBA-15 晶种辅助蒸气转化 骨架组装
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Fitness of Four-Parameter Beta Distribution Function for Forecasting Gold Reserve and Its Production Lifespan in Ghana
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作者 Samuel Kwaku Obeng Christiana C. Nyarko +1 位作者 Lewis Brew K. Sagary Nokoe 《Open Journal of Statistics》 2023年第4期567-593,共27页
Ghana, renowned for its abundant gold reserves, plays a significant role in the global mining industry. Effective management and accurate forecasting of these reserves are vital for sustainable resource utilization an... Ghana, renowned for its abundant gold reserves, plays a significant role in the global mining industry. Effective management and accurate forecasting of these reserves are vital for sustainable resource utilization and economic planning. Forecasting gold reserves and estimating their production lifespan are complex tasks that require robust statistical models capable of capturing the underlying dynamics of gold deposit accumulation and extraction. To this end, the four-parameter Beta distribution function emerges as a promising candidate due to its flexibility and ability to handle non-negative data. This research aims to investigate the fitness and applicability of the four-parameter Beta distribution function for forecasting Ghana’s gold reserves and estimating the production lifespan of this precious resource. The empirical paper relied mainly on quarterly secondary datasets on gold reserve between the years 2009 and 2022 secured from the Minerals Commission of Ghana, Accra. Several known statistical distributions including Beta, Weibull, Normal, Logistic and Gamma were explored with Maximum Likelihood Estimation (MLE) and evaluated using model selection criteria as AIC and BIC. Goodness of Fits were evaluated using Kolmogorov-Smirnov Test (K-S), Cramer-Von Mises Statistic and Anderson-Darling Statistic. Based on the analysis conducted, the four-parameter Beta distribution provided the best fit for gold reserve in Ghana. At a 99.9% confidence level and considering the current annual average gold production estimate of 3,700,031.248 to 4,302,647.888 ounces, the projected lifespan of gold production in Ghana extends to the year 1,953,765. This astounding estimate suggests that the country’s gold reserves are expected to sustain production for an extended period, providing a critical resource for economic development and supporting the mining industry well into the distant future. 展开更多
关键词 Gold Reserve Four-Parameter beta Distribution function Goodness of Fit Statistics
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Fitness of Four-Parameter Beta Distribution Function for Forecasting Gold Reserve and Its Production Lifespan in Ghana
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作者 Samuel Kwaku Obeng Christiana C. Nyarko +1 位作者 Lewis Brew K. Sagary Nokoe 《Open Journal of Endocrine and Metabolic Diseases》 2023年第4期567-593,共27页
Ghana, renowned for its abundant gold reserves, plays a significant role in the global mining industry. Effective management and accurate forecasting of these reserves are vital for sustainable resource utilization an... Ghana, renowned for its abundant gold reserves, plays a significant role in the global mining industry. Effective management and accurate forecasting of these reserves are vital for sustainable resource utilization and economic planning. Forecasting gold reserves and estimating their production lifespan are complex tasks that require robust statistical models capable of capturing the underlying dynamics of gold deposit accumulation and extraction. To this end, the four-parameter Beta distribution function emerges as a promising candidate due to its flexibility and ability to handle non-negative data. This research aims to investigate the fitness and applicability of the four-parameter Beta distribution function for forecasting Ghana’s gold reserves and estimating the production lifespan of this precious resource. The empirical paper relied mainly on quarterly secondary datasets on gold reserve between the years 2009 and 2022 secured from the Minerals Commission of Ghana, Accra. Several known statistical distributions including Beta, Weibull, Normal, Logistic and Gamma were explored with Maximum Likelihood Estimation (MLE) and evaluated using model selection criteria as AIC and BIC. Goodness of Fits were evaluated using Kolmogorov-Smirnov Test (K-S), Cramer-Von Mises Statistic and Anderson-Darling Statistic. Based on the analysis conducted, the four-parameter Beta distribution provided the best fit for gold reserve in Ghana. At a 99.9% confidence level and considering the current annual average gold production estimate of 3,700,031.248 to 4,302,647.888 ounces, the projected lifespan of gold production in Ghana extends to the year 1,953,765. This astounding estimate suggests that the country’s gold reserves are expected to sustain production for an extended period, providing a critical resource for economic development and supporting the mining industry well into the distant future. 展开更多
关键词 Gold Reserve Four-Parameter beta Distribution function Goodness of Fit Statistics
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响应面模型用于Beta分子筛催化剂蜂窝状整体式成型的研究
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作者 韩莹莹 王宁 +1 位作者 陈标华 徐瑞年 《石油炼制与化工》 CAS CSCD 北大核心 2024年第6期83-91,共9页
Beta分子筛由于具有独特的三维十二元环孔道结构,可提供更多活性组分附着位点,是在实际应用中具有优异性能的工业催化剂。在工业使用中,蜂窝整体式催化剂具有通量高、流场均匀、压降小、不易堵塞的优点,是气固或者液固催化反应的最优解... Beta分子筛由于具有独特的三维十二元环孔道结构,可提供更多活性组分附着位点,是在实际应用中具有优异性能的工业催化剂。在工业使用中,蜂窝整体式催化剂具有通量高、流场均匀、压降小、不易堵塞的优点,是气固或者液固催化反应的最优解决方案。但由于Beta分子筛吸水率高,收缩率大,导致蜂窝成型困难,严重限制了Beta分子筛的工业应用。基于此,选择拟薄水铝石(SB粉)为黏结剂、硝酸为胶溶剂、田菁粉为助挤剂,在水粉比为0.6的条件下制备一系列蜂窝整体式成型Beta分子筛催化剂,基于响应面法,评价了各原料的配比对蜂窝整体式催化剂机械强度的影响,得到了催化剂的机械强度与3个因素(黏结剂用量、胶溶剂用量、助挤剂用量)之间关系的二阶多项式近似模型函数。将试验结果与预测值进行对比,证明了预测模型的可靠性,并利用该模型找到最优的Beta分子筛蜂窝成型条件为SB粉质量分数36.1%、硝酸质量分数8.4%、田菁粉质量分数4.7%。 展开更多
关键词 beta分子筛 蜂窝整体式催化剂 响应面法
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基于Beta函数的温度分量模型在混凝土拱坝变形监控中的应用
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作者 胡恢武 杨威 +2 位作者 彭嘉畅 巫殷旺 卢祥 《大坝与安全》 2024年第3期35-40,56,共7页
混凝土拱坝由于具有特殊的超静定壳体结构,对温度尤其敏感,因此拱坝变形监控模型中的温度分量对模型综合性能有显著影响。使用常见的周期三角函数和平均温度等传统温度分量构建方法,无法很好地表示拱坝坝体内部的温度分布与外界温度的... 混凝土拱坝由于具有特殊的超静定壳体结构,对温度尤其敏感,因此拱坝变形监控模型中的温度分量对模型综合性能有显著影响。使用常见的周期三角函数和平均温度等传统温度分量构建方法,无法很好地表示拱坝坝体内部的温度分布与外界温度的滞后效应。因此,提出了一种新的温度滞后特性模拟方法,采用Beta分布来描述滞后影响,并基于Beta函数建立了混凝土拱坝变形监控模型。将基于Beta函数的温度分量模型应用于某拱坝变形监控模型的建立,结果表明监控模型的拟合精度和预测精度均优于传统模型,并表征了前期气温对沿拱向坝体测点变形的影响权重分布,描述了气温对坝体变形的滞后效应。 展开更多
关键词 混凝土拱坝 温度分量 beta函数 变形监控模型
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Combining stochastic density functional theory with deep potential molecular dynamics to study warm dense matter 被引量:1
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作者 Tao Chen Qianrui Liu +2 位作者 Yu Liu Liang Sun Mohan Chen 《Matter and Radiation at Extremes》 SCIE EI CSCD 2024年第1期44-57,共14页
In traditional finite-temperature Kohn–Sham density functional theory(KSDFT),the partial occupation of a large number of high-energy KS eigenstates restricts the use of first-principles molecular dynamics methods at ... In traditional finite-temperature Kohn–Sham density functional theory(KSDFT),the partial occupation of a large number of high-energy KS eigenstates restricts the use of first-principles molecular dynamics methods at extremely high temperatures.However,stochastic density functional theory(SDFT)can overcome this limitation.Recently,SDFT and the related mixed stochastic–deterministic density functional theory,based on a plane-wave basis set,have been implemented in the first-principles electronic structure software ABACUS[Q.Liu and M.Chen,Phys.Rev.B 106,125132(2022)].In this study,we combine SDFT with the Born–Oppenheimer molecular dynamics method to investigate systems with temperatures ranging from a few tens of eV to 1000 eV.Importantly,we train machine-learning-based interatomic models using the SDFT data and employ these deep potential models to simulate large-scale systems with long trajectories.Subsequently,we compute and analyze the structural properties,dynamic properties,and transport coefficients of warm dense matter. 展开更多
关键词 STOCHASTIC theory functionAL
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The Probability Density Function Related to Shallow Cumulus Entrainment Rate and Its Influencing Factors in a Large-Eddy Simulation 被引量:2
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作者 Lei ZHU Chunsong LU +5 位作者 Xiaoqi XU Xin HE Junjun LI Shi LUO Yuan WANG Fan WANG 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2024年第1期173-187,共15页
The process of entrainment-mixing between cumulus clouds and the ambient air is important for the development of cumulus clouds.Accurately obtaining the entrainment rate(λ)is particularly important for its parameteri... The process of entrainment-mixing between cumulus clouds and the ambient air is important for the development of cumulus clouds.Accurately obtaining the entrainment rate(λ)is particularly important for its parameterization within the overall cumulus parameterization scheme.In this study,an improved bulk-plume method is proposed by solving the equations of two conserved variables simultaneously to calculateλof cumulus clouds in a large-eddy simulation.The results demonstrate that the improved bulk-plume method is more reliable than the traditional bulk-plume method,becauseλ,as calculated from the improved method,falls within the range ofλvalues obtained from the traditional method using different conserved variables.The probability density functions ofλfor all data,different times,and different heights can be well-fitted by a log-normal distribution,which supports the assumed stochastic entrainment process in previous studies.Further analysis demonstrate that the relationship betweenλand the vertical velocity is better than other thermodynamic/dynamical properties;thus,the vertical velocity is recommended as the primary influencing factor for the parameterization ofλin the future.The results of this study enhance the theoretical understanding ofλand its influencing factors and shed new light on the development ofλparameterization. 展开更多
关键词 large-eddy simulation cumulus clouds entrainment rate probability density functions spatial and temporal distribution
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Probability Laws Derived from the Gamma Function
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作者 Lansana Toure Soumaila Conde 《Open Journal of Statistics》 2024年第1期106-118,共13页
Several densities or probability laws of continuous random variables derive from the Euler Gamma function. These laws form the basis of sampling theory, namely hypothesis testing and estimation. Namely the gamma, beta... Several densities or probability laws of continuous random variables derive from the Euler Gamma function. These laws form the basis of sampling theory, namely hypothesis testing and estimation. Namely the gamma, beta, and Student law, through the chi-square law and the normal law are all distributions resulting from applications of Euleur functions. 展开更多
关键词 Gamma function beta function PROBABILITY Degree of Freedom
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Deterministic processes drive turnover-dominated beta diversity of breeding birds along the central Himalayan elevation gradient
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作者 Zhifeng Ding Jianchao Liang +3 位作者 Le Yang Cong Wei Huijian Hu Xingfeng Si 《Avian Research》 SCIE CSCD 2024年第2期163-171,共9页
Beta diversity,the variation of community composition among sites,bridges alpha and gamma diversity and can reveal the mechanisms of community assembly through applying distance-decay models and/or partitioning beta d... Beta diversity,the variation of community composition among sites,bridges alpha and gamma diversity and can reveal the mechanisms of community assembly through applying distance-decay models and/or partitioning beta diversity into turnover and nestedness components from functional and phylogenetic perspectives.Mountains as the most natural experiment system provide good opportunities for exploring beta diversity patterns and the underlying ecological processes.Here,we simultaneously consider distance-decay models and multiple di-mensions of beta diversity to examine spatial variations of bird communities,and to evaluate the relative importance of niche-based and neutral community assembly mechanisms along a 3600-m elevational gradient in the central Himalayas,China.Our results showed that species turnover dominates taxonomic,functional,and phylogenetic beta diversity.We observed strongest evidence of spatial distance decays in taxonomic similarities of birds,followed by its phylogenetic and functional analogues.Turnover component was highest in taxonomic beta diversity,while nestedness component was highest in functional beta diversity.Further,all correlations of assemblage similarity with climatic distance were higher than that with spatial distances.Standardized values of overall taxonomic,functional,and phylogenetic beta diversity and their turnover components increase with increasing elevational distance,while the standardized values of taxonomic and phylogenetic nestedness decreased with increasing elevational distance.Our results highlighted the niche-based deterministic processes in shaping elevational bird diversity patterns that were determined by the relative roles of decreasing trend of environmental filtering and increasing trend of limiting similarity along elevation distances. 展开更多
关键词 beta diversity BIRD Community assembly functional trait HIMALAYA Nestedenss Phylogenetic distance TURNOVER
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Greatly enhanced corrosion/wear resistances of epoxy coating for Mg alloy through a synergistic effect between functionalized graphene and insulated blocking layer 被引量:1
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作者 Z.Y.Xue X.J.Li +3 位作者 J.H.Chu M.M.Li D.N.Zou L.B.Tong 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2024年第1期332-344,共13页
The poor corrosion and wear resistances of Mg alloys seriously limit their potential applications in various industries.The conventional epoxy coating easily forms many intrinsic defects during the solidification proc... The poor corrosion and wear resistances of Mg alloys seriously limit their potential applications in various industries.The conventional epoxy coating easily forms many intrinsic defects during the solidification process,which cannot provide sufficient protection.In the current study,we design a double-layer epoxy composite coating on Mg alloy with enhanced anti-corrosion/wear properties,via the spin-assisted assembly technique.The outer layer is functionalized graphene(FG)in waterborne epoxy resin(WEP)and the inner layer is Ce-based conversion(Ce)film.The FG sheets can be homogeneously dispersed within the epoxy matrix to fill the intrinsic defects and improve the barrier capability.The Ce film connects the outer layer with the substrate,showing the transition effect.The corrosion rate of Ce/WEP/FG composite coating is 2131 times lower than that of bare Mg alloy,and the wear rate is decreased by~90%.The improved corrosion resistance is attributed to the labyrinth effect(hindering the penetration of corrosive medium)and the obstruction of galvanic coupling behavior.The synergistic effect derived from the FG sheet and blocking layer exhibits great potential in realizing the improvement of multi-functional integration,which will open up a new avenue for the development of novel composite protection coatings of Mg alloys. 展开更多
关键词 Mg alloy functionalized graphene Epoxy coating Corrosion/wear resistance Blocking layer
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Impact of stage-specific limb function exercises guided by a selfmanagement education model on arteriovenous fistula maturation status 被引量:1
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作者 Yi Li Li-Jun Huang +1 位作者 Jian-Wen Hou Dan-Dan Hu 《World Journal of Clinical Cases》 SCIE 2024年第14期2316-2323,共8页
BACKGROUND The exercise of limb function is the most economical and safe method to promote the maturation of arteriovenous fistula(AVF).However,due to the lack of a uni-fied exercise standard in China,many patients ha... BACKGROUND The exercise of limb function is the most economical and safe method to promote the maturation of arteriovenous fistula(AVF).However,due to the lack of a uni-fied exercise standard in China,many patients have insufficient awareness of the importance of AVF,leading to poor effectiveness of limb function exercise.The self-management education model can effectively promote patients to take pro-active health-related actions.This study focuses on the characteristics of patients during the peri-AVF period and conducts a phased limb function exercise under the guidance of the self-management education model to observe changes in fac-tors such as the maturity of AVF.AIM To assess the impact of stage-specific limb function exercises,directed by a self-management education model,on the maturation status of AVFs.METHODS This study is a randomized controlled trial involving 74 patients with forearm AVFs from the Nephrology Department of a tertiary hospital in Sichuan Province,China.Patients were randomly divided into an observation group and a control group using a random number table method.The observation group underwent tailored stage-specific limb func-tion exercises,informed by a self-management education model which took into account the unique features of AVF at various stages,in conjunction with routine care.Conversely,the control group was given standard limb function exercises along with routine care.The assessment involves the maturity of AVFs post-intervention,post-operative complications,and the self-management level of the fistula in both groups patients.Analyses were conducted using SPSS version 23.0.Count data were represented by frequency and percentage and subjected to chi-square test comparisons.Measurement data adhering to a normal distribution were presented as mean±SD.The independent samples t-test was utilized for inter-group comparisons,while the paired t-test was used for intra-group comparisons.For measurement data not fitting a normal distribution,the median and interquartile range were presented and analyzed using the Wilcoxon rank sum test.RESULTS At the 8-wk postoperative mark,the observation group demonstrated significantly higher scores in AVF symptom recognition,symptom prevention,and self-management compared to the control group(P<0.05).However,the variance in symptom management scores between the observation and control groups lacked statistical signi-ficance(P>0.05).At 4 wk after the operation,the observation group displayed a superior vessel diameter and depth from the skin of the drainage vessels in comparison to the control group(P<0.05).While the observation group did manifest elevated blood flow rates in the drainage vessels relative to the control group,this distinction was not statistically significant(P>0.05).By the 8-wk postoperative interval,the observation group outperformed the control group with notable enhancements in blood flow rates,vessel diameter,and depth from the skin of drainage vessels(P<0.01).Seven days following the procedure,the observation group manifested significantly diminished limb swelling and an overall reduced complication rate in contrast to the control group(P<0.05).The evaluation of infection,thrombosis,embolism,arterial aneurysm stenosis,and incision bleeding showed no notable differences between the two groups(P>0.05).By the 4-wk postoperative juncture,complications between the observation and control groups were statistically indistinguishable(P>0.05).CONCLUSION Stage-specific limb function exercises,under the guidance of a self-management education model,amplify the capacity of AVF patients to discern and prevent symptoms.Additionally,they expedite AVF maturation and miti-gate postoperative limb edema,underscoring their efficacy as a valuable method for the care and upkeep of AVF in hemodialysis patients. 展开更多
关键词 SELF-MANAGEMENT Education model Stage-specific Limb function exercises Arteriovenous fistula Maturation status
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Transplantation of fibrin-thrombin encapsulated human induced neural stem cells promotes functional recovery of spinal cord injury rats through modulation of the microenvironment 被引量:1
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作者 Sumei Liu Baoguo Liu +4 位作者 Qian Li Tianqi Zheng Bochao Liu Mo Li Zhiguo Chen 《Neural Regeneration Research》 SCIE CAS CSCD 2024年第2期440-446,共7页
Recent studies have mostly focused on engraftment of cells at the lesioned spinal cord,with the expectation that differentiated neurons facilitate recovery.Only a few studies have attempted to use transplanted cells a... Recent studies have mostly focused on engraftment of cells at the lesioned spinal cord,with the expectation that differentiated neurons facilitate recovery.Only a few studies have attempted to use transplanted cells and/or biomaterials as major modulators of the spinal cord injury microenvironment.Here,we aimed to investigate the role of microenvironment modulation by cell graft on functional recovery after spinal cord injury.Induced neural stem cells reprogrammed from human peripheral blood mononuclear cells,and/or thrombin plus fibrinogen,were transplanted into the lesion site of an immunosuppressed rat spinal cord injury model.Basso,Beattie and Bresnahan score,electrophysiological function,and immunofluorescence/histological analyses showed that transplantation facilitates motor and electrophysiological function,reduces lesion volume,and promotes axonal neurofilament expression at the lesion core.Examination of the graft and niche components revealed that although the graft only survived for a relatively short period(up to 15 days),it still had a crucial impact on the microenvironment.Altogether,induced neural stem cells and human fibrin reduced the number of infiltrated immune cells,biased microglia towards a regenerative M2 phenotype,and changed the cytokine expression profile at the lesion site.Graft-induced changes of the microenvironment during the acute and subacute stages might have disrupted the inflammatory cascade chain reactions,which may have exerted a long-term impact on the functional recovery of spinal cord injury rats. 展开更多
关键词 biomaterial FIBRINOGEN functional recovery induced neural stem cell transplantation MICROENVIRONMENT MICROGLIA spinal cord injury THROMBIN
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Pt/Beta催化剂上Pt金属中心/酸中心浓度比对加氢异构化性能的影响
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作者 郭凯 马爱增 +4 位作者 罗一斌 王子健 邢恩会 李金芝 李大东 《石油学报(石油加工)》 EI CAS CSCD 北大核心 2024年第1期12-22,共11页
以工业Beta沸石为载体,负载不同含量的Pt,得到了不同金属中心/酸中心浓度比(c_(M)/c_(A))的催化剂,对其进行物化表征,并以正庚烷为模型化合物对不同c_(M)/c_(A)催化剂进行异构化反应性能评价。结果表明:Pt粒子均匀地负载在沸石的外表面... 以工业Beta沸石为载体,负载不同含量的Pt,得到了不同金属中心/酸中心浓度比(c_(M)/c_(A))的催化剂,对其进行物化表征,并以正庚烷为模型化合物对不同c_(M)/c_(A)催化剂进行异构化反应性能评价。结果表明:Pt粒子均匀地负载在沸石的外表面上,对沸石结构没有影响,酸性略有下降。对于催化剂的正庚烷异构化反应活性,当催化剂c_(M)/c_(A)小于0.037时,反应过程由金属中心数量控制,产生大量多支链异构体产物和裂化产物;当c_(M)/c_(A)大于0.285时,反应过程由酸中心数量控制,有氢解反应发生。在反应压力为0.4 MPa、反应温度为207℃、质量空速为1.0 h^(-1)、氢/烃摩尔比为5、催化剂质量为1.0 g的条件下,当催化剂c_(M)/c_(A)为0.266、正庚烷转化率为70.75%时,异构体总选择性为95.14%,总收率为67.31%,其中多支链异构体收率为15.63%,裂化产物收率低于5%。 展开更多
关键词 beta沸石 异构化反应 Pt含量 正庚烷 金属中心 酸中心
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Production of linear alkylbenzene over Ce containing Beta zeolites
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作者 Shiqi Zhang Shengzhi Gan +1 位作者 Baoyu Liu Jinxiang Dong 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2024年第3期220-227,共8页
Ce-encapsulated Beta zeolite was synthesized by a one-pot hydrothermal method with citric acid complexing Ce in the absence of Na species.Additional citric acid can effectively prevent the deposition of Ce species dur... Ce-encapsulated Beta zeolite was synthesized by a one-pot hydrothermal method with citric acid complexing Ce in the absence of Na species.Additional citric acid can effectively prevent the deposition of Ce species during the hydrothermal synthesis of zeolites,leading to uniform distribution of Ce cluster in the framework of Beta zeolites.Moreover,the sodium-free synthesis system resulted that the Brønsted acid sites were mainly located on the straight channels and external surface of Beta zeolites,improving the utilization of Brønsted acid sites.In addition,Ce encapsulated Beta zeolites showed enhanced activity and robust stability in the alkylation of benzene with 1-dodecene based on the synergistic effect between Ce species and Brønsted acid sites,which pave the way for its practical application in the production of alkylbenzene. 展开更多
关键词 beta zeolites CATALYSIS ALKYLATION Long-chain olefins
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Small but big leaps towards neuroglycomics:exploring N-glycome in the brain to advance the understanding of brain development and function
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作者 Boyoung Lee Hyun Joo An 《Neural Regeneration Research》 SCIE CAS CSCD 2024年第3期489-490,共2页
Glycosylation is a process that involves the addition of sugar moieties or glycans to different types of molecules,including proteins,lipids,and nucleic acids.Among these,protein glycosylation is one of the most preva... Glycosylation is a process that involves the addition of sugar moieties or glycans to different types of molecules,including proteins,lipids,and nucleic acids.Among these,protein glycosylation is one of the most prevalent forms of post-translational modification,playing a crucial role in biological complexity.With more than ten monosaccharides identified within mammalian brain cells and more than 1×1012 possible combinations,the heterogeneity of glycosylation is extensive(Conroy et al.,2021).The diversity of glycans and the complexity of their structures allow for a wide range of protein functions.N-glycans are one of the most abundant forms of glycans and are involved in various cellular functions.N-glycans can be added to proteins at specific sequons,Asn-X-Ser/Thr,and are classified into three main types in mature glycoproteins:high mannose,complex,and hybrid.High mannose N-glycans consist of 5-9 mannose residues linked to a chitobiose core and undergo processing into complex or hybrid forms in the Golgi apparatus(Varki et al.,2017).Complex N-glycans are more diverse and contain various branched structures such as antennae with fucose,galactose,and sialic acid residues.Hybrid N-glycans contain one or more complex branches in conjunction with an oligomannose branch(Fisher and Ungar,2016).Understanding the specific functions of these different types of N-glycans in protein regulation,folding,and function is an active area of research in the life sciences,including glycobiology. 展开更多
关键词 functions function apparatus
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Emerging insights into the function of very long chain fatty acids at cerebellar synapses
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作者 Martin-Paul Agbaga Mohiuddin Ahmad 《Neural Regeneration Research》 SCIE CAS 2025年第6期1709-1710,共2页
Very long chain-saturated and-polyunsaturated fatty acids(VLC-SFA and VLC-PUFA, respectively) are a functionally important class of fatty acids containing 28 carbons or more in their acyl chain. They are synthesized b... Very long chain-saturated and-polyunsaturated fatty acids(VLC-SFA and VLC-PUFA, respectively) are a functionally important class of fatty acids containing 28 carbons or more in their acyl chain. They are synthesized by the elongation of very long fatty acids-4(ELOVL4) enzyme, expressed mainly in the brain, retina, skin, testes, and meibomian gland, where these fatty acids are found(Agbaga et al., 2008). Further, these organs exhibit tissuespecific VLC-PUFA and VLC-SFA biosynthesis and incorporation into complex lipids for specific functions. In the brain, skin, and Meibomian glands, the ELOVL4 mainly makes VLC-SFA, which are incorporated into complex sphingolipids. In the retina, the ELOVL4 makes VLC-PUFA that are incorporated into phosphatidylcholine, that are critical for visual function, while in testes and sperm, the VLC-PUFA are incorporated into sphingolipids that are critical for fertility(Yeboah et al., 2021). 展开更多
关键词 functionS function INSIGHT
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