Linear correlation

线性相关
  • 文章类型: Journal Article
    背景:脉搏间隔是心理和生理健康的生物标志物。现在可以使用手机应用程序评估脉搏间隔,这扩展了研究人员在现实世界中评估脉搏间隔的能力。在实施之前,应建立测量精度。
    目的:这项调查评估了LightHeart移动应用程序在健康年轻人中测量脉搏间隔和脉搏率变异性的有效性。
    方法:通过将LightHeart获得的脉搏间隔和正常脉搏间隔的SD与金标准进行比较来评估有效性,心电图(ECG),在14名年轻健康个体中(平均年龄24岁,SD5岁;n=9,64%女性)坐姿。
    结果:平均脉搏间隔(轻度心脏:859,SD113ms;ECG:857,SD112ms)显示出强的正线性相关(r=0.99;P<.001)和技术之间的强一致性(组内相关系数=1.00,95%CI0.99-1.00)。Bland-Altman图显示了用LightHeart和ECG测得的平均脉搏间隔的良好一致性,具有固定偏差的证据(-1.56,SD1.86;95%CI-5.2至2.1ms),这表明LightHeart稍微高估了脉搏间隔。当Bland-Altman图为每个参与者的逐次搏动脉搏间隔数据构建时,所有参与者在LightHeart和ECG之间表现出非常一致的结果,没有证据表明测量之间存在固定偏倚.心率变异性,通过正常脉搏间隔的SD评估,技术之间证明了很强的一致性(轻心脏:平均73,SD23ms;心电图:平均73,SD22ms;r=0.99;P<.001;组内相关系数=0.99,95%CI0.97-1.00)。
    结论:这项研究提供了证据,表明LightHeart移动应用程序可以有效地测量健康年轻人的脉搏间隔和心率变异性。
    BACKGROUND: Pulse interval is a biomarker of psychological and physiological health. Pulse interval can now be assessed using mobile phone apps, which expands researchers\' ability to assess pulse interval in the real world. Prior to implementation, measurement accuracy should be established.
    OBJECTIVE: This investigation evaluated the validity of the Light Heart mobile app to measure pulse interval and pulse rate variability in healthy young adults.
    METHODS: Validity was assessed by comparing the pulse interval and SD of normal pulse intervals obtained by Light Heart to the gold standard, electrocardiogram (ECG), in 14 young healthy individuals (mean age 24, SD 5 years; n=9, 64% female) in a seated posture.
    RESULTS: Mean pulse interval (Light Heart: 859, SD 113 ms; ECG: 857, SD 112 ms) demonstrated a strong positive linear correlation (r=0.99; P<.001) and strong agreement (intraclass correlation coefficient=1.00, 95% CI 0.99-1.00) between techniques. The Bland-Altman plot demonstrated good agreement for the mean pulse interval measured with Light Heart and ECG with evidence of fixed bias (-1.56, SD 1.86; 95% CI -5.2 to 2.1 ms), suggesting that Light Heart overestimates pulse interval by a small margin. When Bland-Altman plots were constructed for each participant\'s beat-by-beat pulse interval data, all participants demonstrated strong agreement between Light Heart and ECG with no evidence of fixed bias between measures. Heart rate variability, assessed by SD of normal pulse intervals, demonstrated strong agreement between techniques (Light Heart: mean 73, SD 23 ms; ECG: mean 73, SD 22 ms; r=0.99; P<.001; intraclass correlation coefficient=0.99, 95% CI 0.97-1.00).
    CONCLUSIONS: This study provides evidence to suggest that the Light Heart mobile app provides valid measures of pulse interval and heart rate variability in healthy young adults.
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  • 文章类型: Journal Article
    立体操纵是分子识别中的已知概念,但目前没有将立体与受体-阴离子复合物的稳定性或结合阴离子的反应性相关的线性自由能关系。类似于阳离子配位化学中的托尔曼锥角,我们探索如何定义和关联有机三氟硼酸酯(R-BF3-)的锥角与观察到的氰星形阴离子结合的亲和力。我们将类比扩展到对反应性及其在阴离子结合时如何变化的罕见研究。阴离子上的取代基用于定义锥角,θ。研究了一系列10种阴离子,包括乙炔基阴离子,乙烯,和乙基取代基,它们被选择来调整整个SP的空间体积,sp2和sp3杂化了带有0、1和2个氢原子的a-碳。对于具有大于-BF3-头基的取代基的阴离子,观察到亲和力与锥角之间的线性关系。这种相关性预测两个新阴离子的亲和力在±5%以内。我们探讨了络合如何影响氟化物交换的反应性。氟化物从R-BF3-转移到路易斯酸三苯基硼烷的产率与锥角相关。我们预测其他刚性大环,比如市售的班布苏里,可以遵循这些趋势。
    Steric manipulation is a known concept in molecular recognition but there is currently no linear free energy relationship correlating sterics to the stability of receptor-anion complexes nor to the reactivity of the bound anion. By analogy to Tolman cone angles in cation coordination chemistry, we explore how to define and correlate cone angles of organo-trifluoroborates (R-BF3 -) to the affinities observed for cyanostar-anion binding. We extend the analogy to a rare investigation of the anion\'s reactivity and how it changes upon binding. The substituent on the anion is used to define the cone angle, θ. A series of 10 anions were studied including versions with ethynyl, ethylene, and ethyl substituents to tune steric bulk across the sp, sp2 and sp3 hybridized α-carbons bearing 0, 1 and 2 hydrogen atoms. A linear relationship between affinity and cone angle is observed for anions bearing substituents larger than the -BF3 - headgroup. This correlation predicted affinities of two new anions to within ±5 %. We explored how complexation affects the reactivity of fluoride exchange. The yield of fluoride transfer from R-BF3 - to Lewis acid triphenylborane is correlated with cone angle. We predict that other rigid macrocycles, like commercially available bambusuril, could follow these trends.
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  • 文章类型: Journal Article
    本研究旨在从微观水平研究竹材的梯度特性,为提高竹材的利用率提供依据。使用毛竹(Phyllostachysedulis(Carrère)J.Houz。)作为一个研究课题,血管束面积百分比的变化,化学成分,相对结晶度(CR),不同竹条的力学性能,并分析了这些参数之间的相关性。从竹绿色层(BGL)到竹黄色层(BYL),维管束分布由密集变为稀疏。纤维素和木质素质量含量温和下降,半纤维素质量含量逐渐增加。CR显示竹子中间层(BML)>BGL>BYL的顺序。拉伸弹性模量,抗拉强度,弯曲弹性模量,弯曲强度从BGL下降到BYL。对毛竹力学性能的影响程度依次为维管束面积,半纤维素含量,木质素质量含量,密度,和CR,这些因素与力学性能有显著的相关性(p<0.05)。维管束面积对竹材的力学性能有决定性影响。维管束面积和密度与力学性能呈线性关系,木质素质量含量和CR与力学性能呈曲线线性相关。
    This study aimed to investigate the gradient properties of bamboo at the microscopic level and provide a basis for improving the utilization rate of bamboo. Using moso bamboo (Phyllostachys edulis (Carrière) J. Houz.) as a research subject, the variation of vascular bundle area percentage, chemical content, relative crystallinity (CR), mechanical properties of different bamboo slivers, and correlation between those parameters were analyzed. From the bamboo green layer (BGL) to the bamboo yellow layer (BYL), the distribution of vascular bundles changed from dense to sparse. Cellulose and lignin mass content decreased gently, and hemicellulose mass content showed gradual increases. The CR showed an order of bamboo middle layer (BML) > BGL > BYL. The tensile modulus of elasticity, tensile strength, bending modulus of elasticity, and bending strength decreased from BGL to BYL. The order of influence degree on mechanical properties of moso bamboo was vascular bundle area, hemicellulose content, lignin mass content, density, and CR, and these factors correlated with mechanical properties at a significant level (p < 0.05). Vascular bundle area had a decisive effect on the mechanical properties of bamboo. The vascular bundle area and density were linearly correlated with mechanical properties, while the lignin mass content and CR were curve-linearly correlated with mechanical properties.
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  • 文章类型: Journal Article
    在患有1型糖尿病(T1D)的成年人中,时间范围(TIR)[70-180mg/dl]已被提议作为除HbA1c之外的额外度量。这项回顾性单中心队列研究确定了2、4和12周内HbA1c与TIR之间的相关性(TIR2w,TIR4w和TIR12w)在儿科T1D人群中进行咨询之前。共纳入168名T1D儿童。连续血糖监测数据,收集HbA1c和人口统计学变量。我们发现HbA1c和TIR2w之间有很强的线性相关性(R=-0.571),TIR4w(R=-0.603)和TIR12w(R=-0.624)。TIR2w和TIR12w之间存在很强的相关性,HbA1c和高于范围的时间(TAR)以及不同时间点的TIR和TAR。总之,HbA1c和TIR之间有很强的相关性,使TIR成为HbA1c的潜在补充指标。TIR2w似乎是TIR12w的可行替代品。TAR在评估血糖控制方面似乎也很有希望。
    In adults with type 1 diabetes (T1D), time in range (TIR) [70-180 mg/dL] has been proposed as an additional metric besides glycated hemoglobin (HbA1c). This retrospective monocentric cohort study determined the correlation between HbA1c and TIR during the 2, 4, and 12 weeks (TIR2w, TIR4w, and TIR12w) before consultation in a pediatric T1D population. A total of 168 children with T1D were included. Continuous glucose monitoring data, HbA1c, and demographic variables were collected. We found strong linear correlations between HbA1c and TIR2w (R = -0.571), HbA1c and TIR4w (R = -0.603), and between HbA1c and TIR12w (R = -0.624). A strong correlation exists between TIR2w and TIR12w, HbA1c and time above range (TAR), and between TIR and TAR at different time points. In conclusion, a strong correlation was found between HbA1c and TIR, making TIR a potentially complementary metric to HbA1c. TIR2w seems a viable alternative to TIR12w. TAR also seems promising in assessing glycemic control.
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  • 文章类型: Journal Article
    高效且经济实惠的电池需要设计新型有机电极材料,以克服传统使用的无机材料的缺点,和潜在候选人的计算筛选是一个非常有效的方法来确定预期的解决方案,并尽量减少实验测试。在这里,我们提出了DFT高通量计算筛选,其中PUBCHEM数据库中包含的8600万个分子已根据其估计的电化学特征进行了分析和分类。确定了5445名表现最好的候选人,其中,预期2306相对于(Li/Li+)具有高于4V的单电子还原电势。类似地,预测626个分子的单电子能量密度高于800Whkg-1。对某些材料进行的显式计算表明,至少有69个候选物具有高于1300Whkg-1的双电子能量密度。成功的分子被分成几个家族,其中一些已经常用的电极材料,和其他人仍未经实验测试。它们中的大多数是含有共轭CO的小系统,NN,或NC官能团。我们选择的分子为实验家探索有机电极的新材料提供了有价值的起点。
    Efficient and affordable batteries require the design of novel organic electrode materials to overcome the drawbacks of the traditionally used inorganic materials, and the computational screening of potential candidates is a very efficient way to identify prospective solutions and minimize experimental testing. Here we present a DFT high-throughput computational screening where 86 million molecules contained in the PUBCHEM database have been analyzed and classified according to their estimated electrochemical features. The 5445 top-performing candidates were identified, and among them, 2306 are expected to have a one-electron reduction potential higher than 4 V versus (Li/Li+ ). Analogously, one-electron energy densities higher than 800 Whkg-1 have been predicted for 626 molecules. Explicit calculations performed for certain materials show that at least 69 candidates with a two-electron energy density higher than 1300 Whkg-1 . Successful molecules were sorted into several families, some of them already commonly used electrode materials, and others still experimentally untested. Most of them are small systems containing conjugated CO, NN, or NC functional groups. Our selected molecules form a valuable starting point for experimentalists exploring new materials for organic electrodes.
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  • 文章类型: Journal Article
    开发了一种快速HPLC方法来研究药学相关分子片段的疏水性程度。通过这一战略,在早期药物发现计划中,可用于物理化学评估的样品数量减少并不是限制因素。先前合成了所研究的16种酸片段,还通过电位法确定了其实验logD值。对于四个片段,不可能确定这样的性质,因为它们的值在仪器工作范围之外(2 A fast HPLC method was developed to study the hydrophobicity extent of pharmaceutically relevant molecular fragments. By this strategy, the reduced amount of sample available for physico-chemical evaluations in early-phase drug discovery programs does not represent a limiting factor. The sixteen acid fragments investigated were previously synthesized also determining potentiometrically their experimental log D values. For four fragments it was not possible to determine such property since their values were outside of the instrumental working range (2 < pKa  < 12). An RP-HPLC method was therefore optimized. For each scrutinized method, some derived chromatographic indices were calculated, and Pearson\'s correlation coefficient (r) allowed to select the so-called \"φ0 index\" as the best correlating with the log D. The w s p H ${}_w^spH$ was fixed at 3.5 and a modification of some variables [organic modifier (methanol vs. ACN), stationary phase (octyl vs. octadecyl), presence/absence of the additives n-octanol, n-butylamine, and n-octylamine], allowed to select the best correlation conditions, producing a r = 0.94 (p < 0.001). Importantly, the φ0 index enabled the estimation of log D values for four fragments which were unattainable by potentiometric titration. Moreover, a series of molecular descriptors were calculated to identify the chemical characteristics of the fragments explaining the obtained φ0 . The number of hydrogen bond donors and the index of cohesive interaction correlated with the experimental data.
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  • 文章类型: Journal Article
    偏头痛和严重头痛是困扰人类和社会的极为普遍的神经系统疾病。先前的研究表明,DII可能会影响偏头痛的发生,但是相关研究太少,需要更多。本研究旨在确定严重头痛或偏头痛与饮食炎症指数(DII)之间的关系。特别注意年龄和性别差异。
    使用国家健康和营养调查(NHANES)的数据,我们进行了一项横断面研究.此外,我们使用加权多变量逻辑回归模型研究了DII与严重头痛或偏头痛之间的关系,并绘制了有限的三次样条模型来探索它们的线性相关。
    共有13,439人参与了这项研究,其中,2745在过去三个月内经历了严重的头痛或偏头痛。DII与严重头痛或偏头痛呈线性正相关(比值比[OR]=1.05,95%置信区间[CI]=1.01-1.08,p=0.0051)。分层分析表明,这种关系在女性和年龄<60岁的人群中持续存在。ORs为1.08(95%CI=1.04-1.13,p=0.0004)和1.05(95%CI=1.01-1.09,p=0.0071),分别。
    我们发现更高水平的DII与偏头痛发作的可能性增加显著相关,特别是在妇女和中青年人群中。需要进一步的研究来验证和扩展我们的结果。
    UNASSIGNED: Migraine and severe headaches are extremely prevalent neurological disorders that plague humans and society. Prior research has revealed that DII may affect the occurrence of migraines, but there are too few relevant studies and more are required. This study aimed to determine the association between severe headache or migraine and the Dietary Inflammatory Index (DII), with particular attention to age and gender differences.
    UNASSIGNED: Using data from the National Health and Nutrition Examination Survey (NHANES), we performed a cross-sectional study. In addition, we investigated the association between DII and severe headache or migraine using weighted multivariate logistic regression models, and restricted cubic splines models were plotted to explore their linear correlation.
    UNASSIGNED: There were a total of 13,439 people participating in the study, and of those, 2745 experienced a severe headache or migraine within the previous three months. The DII was linearly and positively correlated with severe headache or migraine (odds ratio [OR] = 1.05, 95% confidence interval [CI] = 1.01-1.08, p = 0.0051). Stratified analysis showed that this relationship persisted among women and those aged < 60 years, with ORs of 1.08 (95% CI = 1.04-1.13, p = 0.0004) and 1.05 (95% CI = 1.01-1.09, p = 0.0071), respectively.
    UNASSIGNED: We found that greater levels of DII were significantly related to an increased likelihood of migraine onset, especially among women and young and middle-aged populations. Further research is required to validate and expand upon our results.
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  • 文章类型: Journal Article
    当受试者在隐蔽的地点对目标做出反应时,哪些神经元信号可以预测反应时间?尽管最近的研究表明峰值率不能预测,这仍然是一个非常有争议的问题。因此,当猕猴执行隐蔽的空间注意力任务时,我们记录了额叶眼场(FEF)神经元的单单位活动。我们发现,FEF神经元峰值速率的注意力调节与行为反应时间密切相关。此外,这种相关性已经在目标调光前1秒出现,触发行为反应。在神经元中发现了这种通过尖峰速率预测反应时间的方法,这些神经元显示出目标和干扰物的注意力依赖性增强和抑制的活动,分别,然而在不同程度上跨科目。因此,FEF神经元的峰值速率可以在选择性注意力任务期间的操作行为之前持续地预测反应时间。如此长的预测窗口将有助于开发基于尖峰的脑机接口。
    Which neuronal signal(s) predict reaction times when subjects respond to a target at covertly attended locations? Although recent studies showed that spike rates are not predictive, it remains a highly contested question. Therefore, we record single-unit activity from frontal eye field (FEF) neurons while macaques are performing a covert spatial attention task. We find that the attentional modulation of spike rates of FEF neurons is strongly correlated with behavioral reaction times. Moreover, this correlation already emerges 1 s before target dimming, which triggers the behavioral responses. This prediction of reaction times by spike rates is found in neurons showing attention-dependent enhanced and suppressed activity for targets and distractors, respectively, yet in varying degrees across subjects. Thus, spike rates of FEF neurons can predict reaction times persistently and well before the operant behavior during selective attention tasks. Such long prediction windows will be useful for developing spike-based brain-machine interfaces.
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  • 文章类型: Journal Article
    目的:研究X线平片上的层间间隙大小与腰椎管狭窄(LSS)之间的相关性。
    方法:本研究包括100例LSS患者和100例无LSS的正常参与者。在平片上测量腰椎层间参数。在CT和MRI上测量椎管参数。在LSS和对照组之间比较这些图像参数。层间参数之间的线性相关性,分析椎管参数和Oswestry残疾指数(ODI)。分析了诊断L3/4和L4/5症状性LSS的层间参数的临界值。
    结果:L1/2层间宽度除外,LSS组的所有椎板间和椎管相关参数均明显小于对照组。除L1/2层间宽度和L5/S1层间高度外,在各个腰椎层面,所有椎间参数与椎管参数均具有显著正线性相关性.对于有症状的LSS的诊断,L4/5层间宽度的截止值,高度和面积为18.46毫米,11.37mm和134.05mm2,而15.78mm,L3/4中的13.59mm和157.98mm2。在L4/5LSS的情况下,椎管大小和椎间大小与ODI没有线性相关。
    结论:X线片上的腰椎层间间隙大小与发育性和退行性LSS呈正线性相关,除L1/2层间宽度和L5/S1层间高度外。腰椎平片可以通过评估层间空间大小来预测和帮助诊断LSS。
    方法:III.
    Investigating the correlation between the interlaminar space size on plain radiograph and lumbar spinal stenosis (LSS).
    100 Patients with LSS and 100 normal participants without LSS were included in this study. Lumbar interlaminar parameters were measured on plain radiographs. Spinal canal parameters were measure on CT and MRI. These image parameters were compared between LSS and control group. The linear correlation among interlaminar parameters, spinal canal parameters and Oswestry Disability Index (ODI) were analyzed. The cut-off values of interlaminar parameters for diagnosing L3/4 and L4/5 symptomatic LSS were analyzed.
    Excepting for L1/2 interlaminar width, all interlaminar and spinal canal related parameters in LSS group were significantly smaller than those in control group. Excepting for L1/2 interlaminar width and L5/S1 interlaminar height, all interlaminar parameters had significantly positive linear correlation with spinal canal parameters accordingly in each lumbar level. For diagnosis of symptomatic LSS, The cut off values of L4/5 interlaminar width, height and area were 18.46 mm, 11.37 mm and 134.05 mm2 while 15.78 mm, 13.59 mm and 157.98 mm2 in L3/4. Both spinal canal size and interlaminar size had no linear correlation with ODI in cases of L4/5 LSS.
    Lumbar interlaminar space size on plain radiograph has positive linear correlation with developmental and degenerative LSS, excepting for L1/2 interlaminar width and L5/S1 interlaminar height. Lumbar plain radiograph can be a feasible way for predicting and helping to diagnose LSS through evaluating the interlaminar space size.
    III.
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  • 文章类型: Journal Article
    The idealized urea electrocatalyst is crucial to boost the CN coupling reaction and simultaneously suppress their isolated reduction process after adsorbing N2 and CO2 molecules. Therefore, the dispersed MN3 -M\'N4 moiety is investigated systematically, including 26 homonuclear and 650 heteronuclear di-metal systems. After, 205 stable systems are selected using lowest-energy principle and ab initio molecular dynamics simulations. According to three possible pathways, NCON, CO, and OCOH to produce urea, a five-step high-throughput screening method for excellent catalytic activity and a five-aspect high-throughput screening strategy for outstanding catalytic selectivity are proposed, respectively. The potential determined steps and the limiting potential through three pathways are identified. The data indicates both CO pathway and OCOH pathway are more competitive at lower Gibbs free energy. Significantly, the most favorite RuN3 -CoN4 combination possesses an extremely low limiting potential of -0.80 V for urea production, meanwhile it exists a strong foundation for experimental preparation. This work not only broadens electrocatalytic potentiality of developing di-metals as two active sites, but also provides a feasible high-throughput screening recipe for urea production.
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