Superior Mechanical Behavior and Flame Retardancy FRP via a Distribution Controllable 1D/2D Hybrid Nanoclay Synergistic Toughening Strategy

The incorporation of commercial flame retardants into fiber-reinforced polymer(FRP)composites has been proposed as a potential solution to improve the latter’s poor flame resistance.However,this approach often poses a challenge,as it can adversely affect the mechanical properties of the FRP.Thus,balancing the need for improved flame resistance with the preservation of mechanical integrity remains a complex issue in FRP research.Addressing this critical concern,this study introduces a novel additive system featuring a combination of one-dimensional(1D)hollow tubular structured halloysite nanotubes(HNTs)and two-dimensional(2D)polygonal flake-shaped nano kaolinite(NKN).By employing a 1D/2D hybrid kaolinite nanoclay system,this research aims to simultaneously improve the flame retardancy and mechanical properties.This innovative approach offers several advantages.During combustion and pyrolysis processes,the 1D/2D hybrid kaolinite nanoclay system proves effective in reducing heat release and volatile leaching.Furthermore,the system facilitates the formation of reinforcing skeletons through a crosslinking mechanism during pyrolysis,resulting in the development of a compact char layer.This char layer acts as a protective barrier,enhancing the material’s resistance to heat and flames.In terms of mechanical properties,the multilayered polygonal flake-shaped 2D NKN plays a crucial role by impeding the formation of cracks that typically arise from vulnerable areas,such as adhesive phase particles.Simultaneously,the 1D HNT bridges these cracks within the matrix,ensuring the structural integrity of the composite material.In an optimal scenario,the homogeneously distributed 1D/2D hybrid kaolinite nanoclays exhibit remarkable results,with a 51.0%improvement in mode II fracture toughness(GIIC),indicating increased resistance to crack propagation.In addition,there is a 34.5%reduction in total heat release,signifying improved flame retardancy.This study represents a significant step forward in the field of composite materials.The innovative use of hybrid low-dimensional nanomaterials offers a promising avenue for the development of multifunctional composites.By carefully designing and incorporating these nanoclays,researchers can potentially create a new generation of FRP composites that excel in both flame resistance and mechanical strength.

Effects of surface chlorine atoms on charge distribution and reaction barriers for photocatalytic CO_(2)reduction

Photocatalytic CO_(2)reduction to produce high value-added carbon-based fuel has been proposed as a promising approach to mitigate global warming issues.However,the conversion efficiency and product selectivity are still low due to the sluggish dynamics of transfer processes involved in proton-assisted multi-electron reactions.Lowering the formation energy barriers of intermediate products is an effective method to enhance the selectivity and productivity of final products.In this study,we aim to regulate the surface electronic structure of Bi_(2)WO_(6)by doping surface chlorine atoms to achieve effective photocatalytic CO_(2)reduction.Surface Cl atoms can enhance the absorption ability of light,affect its energy band structure and promote charge separation.Combined with DFT calculations,it is revealed that surface Cl atoms can not only change the surface charge distribution which affects the competitive adsorption of H_(2)O and CO_(2),but also lower the formation energy barrier of intermediate products to generate more intermediate*COOH,thus facilitating CO production.Overall,this study demonstrates a promising surface halogenation strategy to enhance the photocatalytic CO_(2)reduction activity of a layered structure Bi-based catalyst.

Designing ultrastable P2/O3-type layered oxides for sodium ion batteries by regulating Na distribution and oxygen redox chemistry

P2/O3-type Ni/Mn-based layered oxides are promising cathode materials for sodium-ion batteries(SIBs)owing to their high energy density.However,exploring effective ways to enhance the synergy between the P2 and 03 phases remains a necessity.Herein,we design a P2/O3-type Na_(0.76)Ni_(0.31)Zn_(0.07)Mn_(0.50)Ti_(0.12)0_(2)(NNZMT)with high chemical/electrochemical stability by enhancing the coupling between the two phases.For the first time,a unique Na*extraction is observed from a Na-rich O3 phase by a Na-poor P2 phase and systematically investigated.This process is facilitated by Zn^(2+)/Ti^(4+)dual doping and calcination condition regulation,allowing a higher Na*content in the P2 phase with larger Na^(+)transport channels and enhancing Na transport kinetics.Because of reduced Na^(+)in the O3 phase,which increases the difficulty of H^(+)/Na^(+) exchange,the hydrostability of the O3 phase in NNZMT is considerably improved.Furthermore,Zn^(2+)/Ti^(4+)presence in NNZMT synergistically regulates oxygen redox chemistry,which effectively suppresses O_(2)/CO_(2) gas release and electrolyte decomposition,and completely inhibits phase transitions above 4.0 V.As a result,NNZMT achieves a high discharge capacity of 144.8 mA h g^(-1) with a median voltage of 3.42 V at 20 mA g^(-1) and exhibits excellent cycling performance with a capacity retention of 77.3% for 1000 cycles at 2000 mA g^(-1).This study provides an effective strategy and new insights into the design of high-performance layered-oxide cathode materials with enhanced structure/interface stability forSIBs.

Application of neutrophil-lymphocyte ratio and red blood cell distribution width in diabetes mellitus complicated with heart failure

BACKGROUND Accumulating clinical evidence has shown that diabetes mellitus(DM)is a serious risk factor for cardiovascular disorders and an important factor for adverse cardiovascular events.AIM To explore the value of the combined determination of the neutrophil-lymphocyte ratio(NLR)and red blood cell distribution width(RDW)in the early diagnosis and prognosis evaluation of DM complicated with heart failure(HF).METHODS We retrospectively analyzed clinical data on 65 patients with type 2 DM(T2DM)complicated with HF(research group,Res)and 60 concurrent patients with uncomplicated T2DM(control group,Con)diagnosed at Zhejiang Provincial People’s Hospital between January 2019 and December 2021.The NLR and RDW values were determined and comparatively analyzed,and their levels in T2DM+HF patients with different cardiac function grades were recorded.The receiver operating characteristic(ROC)curves were plotted to determine the NLR and RDW values(alone and in combination)for the early diagnosis of HF.The correlation between NLR and RDW with the presence or absence of cardiac events was also investigated.RESULTS Higher NLR and RDW levels were identified in the Res vs the Con groups(P<0.05).The NLR and RDW increased gradually and synchronously with the deterioration of cardiac function in the Res group,with marked differences in their levels among patients with grade II,III,and IV HF(P<0.05).ROC curve analysis revealed that NLR combined with RDW detection had an area under the curve of 0.915,a sensitivity of 76.9%,and a specificity of 100%for the early diagnosis of HF.Furthermore,HF patients with cardiac events showed higher NLR and RDW values compared with HF patients without cardiac events.CONCLUSION NLR and RDW were useful laboratory indicators for the early diagnosis of DM complicated with HF,and their joint detection was beneficial for improving diagnostic efficiency.Additionally,NLR and RDW values were directly proportional to patient outcomes.

The application of Gaussian distribution deconvolution method to separate the overlapping signals in the 2D NMR map

The 2D NMR(T_(1)-T_(2))mapping technique,which can be used to separate different proton populations from various sources(hydroxyls,solid organic matter,free water,and free HC)has gained attention in petroleum industry.To separate proton contributions,a fixed straight line is commonly employed to separate different regions representing proton sources on the map.However,some of these regions(Region 1 and 2)might overlap which makes extracting the NMR signal amplitude from these regions inaccurate.In order to solve this issue,in this study,we applied the Gaussian distribution deconvolution method to separate the T_(1)and T_(2)relaxation distributions and then derived the signal amplitude of each region instead of following the common fixed line approach.Next,we employed this method to analyze several shale samples from the literature and compared the results following both methods to verify our methodology.Finally,samples from the Bakken Shale were studied to separate signals from Region 1 and Region 2 and corelated the results with geochemical properties that were obtained from programmed(Rock Eval)pyrolysis.Results demonstrated an improvement in their relation when our approach is employed compared to the fixed line technique to differentiate signal from overlapping regions.This means the Gaussian distribution deconvolution method can be used with confidence to provide us with more accurate petrophysical and geochemical understanding of complex formations.

Effects of Low Energy Argon Ion Implantation on Maize Pollen Germination and the Cytosolic Ca^(2+) Distribution during Pollen Germination Process

To investigate the effect of low energy ion implantation on maize pollen germination and cytosolic Ca2+ distribution during pollen germination process, the argon ion (Ar+) with energy of 30 keV, dose of 0.78 ×1015-13×1015 ion/cm2 was implanted into maize pollen by irradiation, and the germination of pollen and cytosolic Ca2+ distribution during pollen germination process of the Ar+ implanted pollen were studied. The results showed that when been irradiated with Ar+ with dose of 5.2×1015 ion/cm2, the germination rate of maize pollen increased remarkably, while implantation of ions with dose exceeding 5.2×1015 ion/cm2 sharply decreased the germination rate of maize pollen. Meanwhile, tracing of esterified Ca2+ fluorescence probe fluo-3 AM for intact pollen showed that variation of cytosolic Ca2+ concentration was consistent with the change of pollen fertility. The dynamics of cytosolic Ca2+ concentration caused by low energy ion implantation may be concluded as the initial effects of pollen germination.

Numerical simulation of rock pore-throat structure effects on NMR T_2 distribution

We built a three-dimensional irregular network model which can adequately describe reservoir rock pore-throat structures. We carried out numerical simulations to study the NMR T2 distribution of water-saturated rocks. The results indicate that there is a good correlation between T2 distribution and the pore radius frequency histogram. The total T2 distribution can be partitioned into pore body and pore throat parts. The effect of parameters including throat radius, pore-throat ratio, and coordination number of the micro- pore structure on the T2 distribution can be evaluated individually. The result indicates that： 1 ） with the increase of the pore throat radius, the T2 distribution moves toward longer relaxation times and its peak intensity increases; 2） with the increase of the pore-throat ratio, the T2 distribution moves towards longer T2 with the peak intensity increasing and the overlap between pore body T2 and pore throat T2 decreasing; 3） With the increase of connectivity, the short T2 component increases and peak signal intensity decreases slightly.

Quasi-χ~2 Distribution and the Independence of Wishart Distribution

In this paper, the authors generalize the definition of χ 2 distribution and introduce a quasi χ 2 distribution, and then prove several properties of it, find the necessary and sufficient conditions of independence about multivariate normal distributions, matrix normal distributions and two parts of the Wishart distribution.

超高选择性CO_(2)光还原为乙醇的CuNi异核双原子催化剂的精准设计

利用光催化还原技术将CO_(2)定向转化为乙醇(CO_(2)-乙醇)是解决日益严重的环境污染和能源危机的理想途径之一.然而,CO_(2)分子的高化学惰性以及C-C耦合反应的高化学能垒导致目前CO_(2)-乙醇转化反应的产率和选择性较低.因此,设计构建能够快速活化CO_(2)分子并同时促进C-C耦合的光催化材料具有重要研究意义.尽管已有研究表明,Cu+物种在促进C-C耦合方面具有一定优势,但其在催化反应过程中的不稳定性限制了其实际应用.基于上述认识,本文通过理论模拟预测发现,相比于Cu单原子,CuNi异核双原子(CuNi HDAs)不仅在CO_(2)活化及C-C耦合方面更具优势,而且能够有效锚定并固化Cu+物种.因此,本文设计了一种三步合成策略,精准地将Cu单原子锚定在(Ni,Zr)-UiO-66-NH2材料的Ni位上,合成了以CuNi HDAs为活性位点的Cu-(Ni,Zr)-UiO-66-NH2光催化材料.在可见光照射下,Cu-(Ni,Zr)-UiO-66-NH2表现出较好的催化CO_(2)-乙醇转化活性,其乙醇的产率和选择性分别达到~3218μmol·gCu^(-1)·h^(-1)和97.3%.光谱分析和密度泛函理论计算结果表明,Cu-(Ni,Zr)-UiO-66-NH2材料较好的光催化性能来源于CuNi HDAs特殊的电子结构.首先,CuNi HDAs通过CuNi-O界面化学键与吸光组分(Ni,Zr)-UiO-66-NH2相连,利用界面Cu-Ni-O键作为快速电子传输通道,CuNi HDAs能够富集到足够的光生电子用于涉及12电子的CO_(2)-乙醇转化反应,使得乙醇产率大幅提升.其次,Cu,Ni和O三种原子由于电子亲核能的差异,导致CuNi HDAs的电子分布呈现不对称性.这种不对称的电子结构能有效诱导CO_(2)分子的极化,打破其结构的对称性,从而显著降低CO_(2)分子的活化能.再次,相比于Cu单原子,CuNi HDAs对*CO中间体的吸附能力更强,这不仅增强了活性位点表面*CO中间体的覆盖度,还抑制CO的生成,为C-C耦合创造了充分条件.最后,由于Cu-Ni双活性位电子密度的差异,CuNi HDAs表面的C-C耦合反应势能较低,有利于*OCCHO中间体的快速生成,从而使乙醇产物的选择性大幅提升.综上,本文以理论计算模拟为指导,以UiO-66-NH2材料为基底,成功设计并制备了一种具有不对称电子结构的CuNi HDAs光催化材料,实现了高选择性CO_(2)光还原为乙醇.研究表明,CuNi HDAs的不对称结构在促进分子活化和降低C-C耦合反应能垒中起关键作用,同时促进了光生电子在CuNi HDAs活性位的富集.本文的研究结果为在原子尺度上设计并合成高性能的CO_(2)还原光催化剂提供了实验和理论参考.

7元旋转对称2-弹性函数的构造

基于旋转对称轨道的数对分布矩阵的性质,给出了所有7元旋转对称2-弹性函数的具体构造。结果表明,在F_(2)^(7)上有且仅有280个非线性旋转对称2-弹性函数。进一步地,对于任意的奇数k,在F_(2)^(7k)上至少有280个非线性旋转对称2-弹性函数。

血小板和凝血功能对合并2型糖尿病的脓毒症患者发生急性肾损伤的预测价值

目的探讨血小板、凝血功能对合并2型糖尿病的脓毒症(sepsis patients with type 2 diabetes mellitus,T2DM-sepsis)患者发生急性肾损伤(acute kidney injury,AKI)的预测价值。方法选取2015年1月至2021年1月首都医科大学附属北京同仁医院T2DM-sepsis患者257例。根据T2DM-sepsis患者住院期间脓毒症发病7 d内是否发生AKI,将患者分为AKI组与非AKI组。收集两组患者一般资料和临床资料,采用多因素logistic回归方程分析T2DM-sepsis患者发生AKI的影响因素,并采用ROC曲线评估血小板、凝血功能对患者发生AKI的预测价值。结果257例患者中男146例、女111例,年龄32~101岁,平均(77.4±13.2)岁;发生AKI的患者34例(13.2%)。与非AKI组相比,AKI组的序贯器官衰竭评估(sequential organ failure assessment,SOFA)评分、急性生理学和慢性健康状况评价Ⅱ(acute physiology and chronic health evaluationⅡ,APACHEⅡ)评分、血小板分布宽度(platelet distribution width,PDW)、血小板平均体积(mean platelet volume,MPV)、纤维蛋白原降解产物(fibrinogen degradation products,FDP)和D-二聚体(D-dimer,D-D)均较高,PLT较低,差异均有统计学意义(P<0.05)。多因素回归分析结果显示,SOFA评分越高(OR=1.300,95%CI:1.018~1.661,P=0.035)、PDW越高(OR=1.338,95%CI:1.122~1.596,P=0.001)的T2DM-sepsis患者发生AKI的风险越高。SOFA评分和PDW预测患者发生AKI的AUC分别为0.717(95%CI:0.619~0.815,P<0.001)和0.752(95%CI:0.655~0.848,P<0.001)。结论PDW值可作为T2DM-sepsis患者发生AKI风险的评估指标,临床上应特别关注PDW>12.25 fl的T2DM-sepsis患者的治疗和预后。

宽负荷下切圆燃煤锅炉H_(2)S分布特性的数值模拟

锅炉采用空气分级燃烧降低NO_(x)排放的同时也提高了主燃区H_(2)S体积分数。炉墙壁面过高的H_(2)S体积分数是加剧水冷壁高温腐蚀的重要因素。为保障新能源并网发电,大型燃煤机组灵活调峰的需求增加,不同负荷下的水冷壁近壁面H_(2)S分布特性值得关注。通过正交试验分析了切圆燃煤锅炉运行参数对水冷壁近壁面H_(2)S体积分数分布的影响。选取一台超临界600 MW切圆燃煤锅炉建立数值模型,设计L_(16)(4^(5))正交工况,覆盖100%BMCR、75%THA,50%THA以及35%BMCR四种负荷。建立了自定义SO_(x)生成模型以确定燃料硫的析出和转化路径,模型包含多表面反应子模型以描述焦炭与O_(2)/CO_(2)/H_(2)O等3种气体的异相反应,并确定焦炭气化反应消耗量占总消耗量的比例,进而对炉膛H_(2)S空间分布进行了模拟计算。研究表明,近壁面高体积分数H_(2)S区域主要位于投运燃烧器层中最下层燃烧器以下以及最上层燃烧器以上至SOFA层之间,烟气切圆沿炉膛高度增加逐渐增大是造成后一区域H_(2)S体积分数较高的重要原因。35%BMCR负荷下水冷壁重点区域的H_(2)S平均体积分数为364μL/L,明显低于其他负荷。锅炉运行参数对重点区域H_(2)S体积分数影响程度的排序为:锅炉负荷>一次风率>主燃区空气过量系数>假想切圆直径>燃烧器竖直摆角。

基于改进INFO-Bi-LSTM模型的SO_(2)排放质量浓度预测

针对火电机组SO_(2)排放质量浓度的影响因素众多,难以准确预测的问题,提出一种改进向量加权平均(weighted mean of vectors,INFO)算法与双向长短期记忆(bi-directional long short term memory,Bi-LSTM)神经网络相结合的预测模型(改进INFO-Bi-LSTM模型)。采用Circle混沌映射和反向学习产生高质量初始化种群,引入自适应t分布提升INFO算法跳出局部最优解和全局搜索的能力。选取改进INFO-Bi-LSTM模型和多种预测模型对炉内外联合脱硫过程中4种典型工况下的SO_(2)排放质量浓度进行预测,将预测结果进行验证对比。结果表明:改进INFO算法的寻优能力得到提升,并且改进INFO-Bi-LSTM模型精度更高,更加适用于SO_(2)排放质量浓度的预测,可为变工况下的脱硫控制提供控制理论支撑。

Distribution and engulfment behavior of TiB_2 particles or clusters in wedge-shaped copper casting ingot

Wedge-shaped copper casting experiment was conducted to study the engulfment behavior of TiB2 particle and the interaction between particle or cluster and the solid/liquid front in commercial pure aluminum matrix. The experimental results show that the particle size distribution obeys two separate systems in the whole wedge-cast sample. Furthermore, it is found that the big clusters are pushed to the center of the wedge shaped sample and the single particle or small clusters consisting of few particles are engulfed into the α-Al in the area of the sample edge. The cluster degree of particles varies in different areas, and its value is 0.2 and 0.6 for the cluster fraction in the edge and in the center of the wedge sample, respectively. The cluster diameter does not obey the normal distribution but approximately obeys lognormal distribution in the present work. More importantly, in the whole sample, the particle size obeys two separate log-normal distributions.

高含CO_(2)凝析气藏成藏过程中的流体相行为及油环体积预测

成藏后期的CO_(2)充注导致里贝拉区块高含CO_(2)次生凝析气藏的流体相行为十分复杂,油环体积预测难度很大。本文通过流体相平衡模拟、组分梯度分布计算及CO_(2)充注可视化实验,刻画了CO_(2)充注过程中的油气相行为,揭示了油环体积的动态变化规律,建立了基于气顶气组分拟合的高含CO_(2)次生凝析气藏油环体积预测新方法。研究结果表明:1)CO_(2)充注下的油环体积变化分为4个阶段:充注初期,油环以溶胀为主;充注前期,CO_(2)不断置换并萃取油相中的轻质组分,油环体积迅速降低;充注中期,CO_(2)持续萃取油相的轻、中质组分,油环体积缓慢减小;充注后期,CO_(2)-原油组分传质作用明显减弱,压缩效应导致油环体积进一步减小。2)轻质组分的强流动性使气顶气组成均一,重力分异作用使纵向上油环组分呈梯度变化。3)油环体积与气顶气组成和气油比密切相关。4)基于气顶气拟合新方法和不同井深现场勘探预测的油环体积占比分别为19.21%和22.30%,与CO_(2)充注可视化实验获得的油环体积占比(20.60%)较为吻合。

Thorium distribution on the Moon:new insights from Chang’E-2 gamma-ray spectrometer

We present the thorium distribution on the lunar surface derived from observations by the Chang’E-2 gamma-ray spectrometer(CE-2 GRS). This new map shows a similar thorium distribution to previous observations. In combination with this new thorium map and impact cratering model, we investigate the origination of thorium on the Moon’s highlands, which was previously thought to be contributed from Imbrium ejecta. We found that the Imbrium ejecta has a small contribution(~20%–30%) to the thorium on the lunar highlands but most thorium is likely to be indigenous before the deposition of the Imbrium ejecta. This new thorium map also confirms that the eastern highlands have a relatively higher thorium concentration than the western highlands. We propose that the thin crust and large basins on the eastern highlands are responsible for this difference in thorium.

Estimation of Pore Size Distribution by CO_2 Adsorption and Its Application in Physical Activation of Precursors

The CO2 adsorption data may show more than one section in the Dubinin-Radushkevich-Kaganer(DRK) plot if samples had been over-activated. Each section in the plot represents a range of pore size. The whole DRK plot provided information on the pore size distribution(PSD) of a sample, which may be used to monitor the effect of activation conditions in activation processes.

Distribution and relative activity of matrix metalloproteinase-2 in human coronal dentin

The presence of matrix metalloproteinase-2 （MMP-2） in dentin has been reported, but its distribution and activity level in mature human coronal dentin are not well understood. The purpose of this study was to determine the MMP-2 distribution and relative activity in demineralized dentin. Crowns of twenty eight human molars were sectioned into inner （ID）, middle （MD）, and outer dentin （OD） regions and demineralized. MMP-2 was extracted with 0.33 mol·L-1 EDTA/2 mol·L-1 guanidine-HCl, pH 7.4, and MMP-2 concentration was estimated with enzyme-linked immunoabsorbant assay （ELISA）. Further characterization was accomplished by Western blotting analysis and gelatin zymography. The mean concentrations of MMP-2 per mg dentin protein in the dentin regions were significantly different （P=0.043）： 0.9 ng （ID）, 0.4 ng （MD）, and 2.2 ng （OD）, respectively. The pattern of MMP-2 concentration was OD〉ID〉MD. Western blotting analysis detected -66 and -72 kDa immunopositive proteins corresponding to pro- and mature MMP-2, respectively, in the ID and MD, and a -66 kDa protein in the OD. Gelatinolytic activity consistent with MMP-2 was detected in all regions. Interestingly, the pattern of levels of Western blot immunodetection and gelatinolytic activity was MD〉ID〉OD. The eoneentration of MMP-2 in human coronal dentin was highest in the region of dentin that contains the dentinoenamel junction and least in the middle region of dentin. However, levels of Western blot immunodetection and gelatinolytic activity did not correlate with the estimated regional concentrations of MMP-2, potentially indicating region specific protein interactions.

The initial stages of Li_(2)O_(2) formation during oxygen reduction reaction in Li-O_(2) batteries:The significance of Li_(2)O_(2) in charge-transfer reactions within devices

Lithium-oxygen batteries are a promising technology because they can greatly surpass the energy density of lithium-ion batteries.However,this theoretical characteristic has not yet been converted into a real device with high cyclability.Problems with air contamination,metallic lithium reactivity,and complex discharge and charge reactions are the main issues for this technology.A fast and reversible oxygen reduction reaction(ORR)is crucial for good performance of secondary batteries',but the partial knowledge of its mechanisms,especially when devices are concerned,hinders further development.From this perspective,the present work uses operando Raman experiments and electrochemical impedance spectroscopy(EIS)to assess the first stages of the discharge processes in porous carbon electrodes,following their changes cycle by cycle at initial operation.A growth kinetic formation of the discharge product signal(Li_(2)O_(2))was observed with operando Raman,indicating a first-order reaction and enabling an analysis by a microkinetic model.The solution mechanism in the evaluated system was ascribed for an equivalent circuit with three time constants.While the time constant for the anode interface reveals to remain relatively constant after the first discharge,its surface seemed to be more non-uniform.The model indicated that the reaction occurs at the Li_(2)O_(2) surface,decreasing the associated resistance during the initial discharge phase.Furthermore,the growth of Li_(2)O_(2) forms a hetero-phase between Li_(2)O_(2)/electrolyte,while creating a more compact and homogeneous on the Li_(2)O_(2)/cathode surface.The methodology here described thus offers a way of directly probing changes in surface chemistry evolution during cycling from a device through EIS analysis.

2型糖尿病患者血清铁蛋白水平与体脂分布的相关性分析

目的探讨2型糖尿病(T2DM)患者血清铁蛋白水平与体脂分布的关系。方法收集2020年6-11月在兰州大学第一医院内分泌科住院的151例T2DM患者进行回顾性分析。所有患者根据血清铁蛋白水平分为高血清铁蛋白组(n=50)与正常血清铁蛋白组(n=101)。测量两组患者的血糖、血脂,以及内脏脂肪面积(VFA)、皮下脂肪面积(SFA)、肝脂肪、身高、体重和腰围(WC),计算体重指数(BMI)和内脏肥胖指数(VAI),并进行组间比较;采用Pearson或Spearman相关性分析及多元线性回归分析血清铁蛋白水平与体脂分布的相关性。结果高血清铁蛋白组VAI和WC均明显高于正常血清铁蛋白组[分别为3.13(2.16,4.58)vs.2.66(1.66,3.81),(96.66±7.78)cm vs.(91.96±9.75)cm,P<0.05]。高血清铁蛋白组中心性肥胖和血脂异常的患病率明显高于正常血清铁蛋白组(分别为88.0%vs.68.3%,90.0%vs.75.2%,P<0.05),且血糖控制差、胰岛素抵抗的构成比也高于正常血清铁蛋白组(分别为96.0%vs.78.2%、62.0%vs.40.6%,P<0.05),而两组间BMI、VFA、SFA水平,以及降糖药物使用情况和糖尿病慢性并发症差异无统计学意义(P>0.05)。T2DM患者血清铁蛋白水平与VAI、WC、三酰甘油(TG)、空腹血糖(FPG)、糖化血红蛋白(HbA1c)、血脂异常、血清肌酐(SCr)呈正相关(r=0.171、0.207、0.187、0.243、0.270、0.162、0.162,P<0.05),与年龄、性别和糖尿病病程呈负相关(r=-0.191、-0.434、-0.352,P<0.05)。多元线性回归显示,在男性T2DM患者中,糖尿病病程和FPG是血清铁蛋白水平增高的危险因素,但WC及VAI对血清铁蛋白的影响不明显;而在女性T2DM患者中,糖尿病病程、TG和VAI是血清铁蛋白水平增高的危险因素(P<0.05)。结论女性T2DM患者的血脂紊乱和内脏脂肪增加是血清铁蛋白水平增高的危险因素。