BIC

BIC
  • 文章类型: Journal Article
    过渡金属二硫属化物(TMDC)由于其出色的光学特性而处于纳米光子学的最前沿。TMDC的2D架构有助于有效的光吸收和发射,为下一代纳米光子和量子器件提供诱人的潜力。然而,原子薄度限制了它们与光的相互作用量,影响光-物质相互作用和量子效率。2D分层TMDC中的光耦合可以通过与光子结构集成来增强,并且在连续体中支持束联态(BIC)的超表面提供了强大的光场限制,理想的与2DTMDC耦合。这里,我们通过整合TMDC单层展示了增强的光-物质耦合,包括WSe2和MoS2,具有有限面积的膜超表面,导致准BIC耦合TMDC单层的放大和高质量因子(Q因子)自发发射。高Q因子发射在具有几微米尺度的区域上延伸,同时在发射区域上保持高Q因子。值得注意的是,悬浮的有限面积膜超表面,它在空气中是独立的,而不是位于基板上,使辐射损失最小化,同时增强TMDC单层中的光-物质相互作用。此外,TMDC单层内激子的主要面内偶极取向导致发射的独特增强行为,视激励功率而定,当与表现出TE和TM谐振的准BIC模式耦合时。这项工作介绍了一个纳米光子平台,用于膜超表面与2D材料的强大耦合,为开发基于2D材料的纳米光子和量子器件提供了可能性。
    Transition metal dichalcogenides (TMDCs) are at the forefront of nanophotonics because of their exceptional optical characteristics. The 2D architecture of TMDCs facilitates efficient light absorption and emission, holding tantalizing potential for next-generation nanophotonic and quantum devices. Yet, the atomic thinness limits their interaction volume with light, affecting light-matter interaction and quantum efficiency. The light coupling in the 2D layered TMDCs can be enhanced by integration with photonic structure, and the metasurfaces supporting bound states in the continuum (BICs) offer strong confinement of optical fields, ideal for coupling with 2D TMDCs. Here, we demonstrate enhanced light-matter coupling by integrating TMDC monolayers, including WSe2 and MoS2, with a finite-area membrane metasurface, leading to amplified and high-quality-factor (Q-factor) spontaneous emission from quasi-BIC-coupled TMDC monolayers. The high-Q-factor emission extends over an area with a scale of a few micrometers while maintaining the high-Q factor across the emission area. Notably, the suspended finite-area membrane metasurface, which is freestanding in air rather than positioned atop a substrate, minimizes radiation loss while enhancing light-matter interaction in the TMDC monolayer. Furthermore, the predominantly in-plane dipole orientation of excitons within TMDC monolayers results in distinctive enhancement behaviors for emission, contingent on the excitation power, when coupled with quasi-BIC modes exhibiting TE and TM resonances. This work introduces a nanophotonic platform for robust coupling of membrane metasurfaces with 2D materials, offering possibilities for developing 2D material-based nanophotonic and quantum devices.
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  • 文章类型: Journal Article
    强烈的圆二色性(CD)响应的动态控制在工程应用中至关重要,例如偏振操纵,传感,和成像。这里,我们提出并通过实验证明了在二维拓扑保护的超表面中通过连续介质(BIC)中的束束态实现宽带可调谐双CD响应,该超表面由全电介质Si手性光栅结构组成,该结构产生一对混合和退化的BIC模式和圆形二向色模式(CDM)作为CD操纵中的附加自由度。发现当BIC在垂直入射下隐藏时,通过CDM可以在1.6μm处实现近100%的奇异CD峰,而CD峰可以分为两个,其中当BIC模式在倾斜入射下激发时,峰值波长可以通过入射角在180nm的带宽上精确线性调谐。此外,由于BIC将Γ点处的各种偏振状态解耦到K空间中的不同位置,因此在引入手性光栅上的不对称扰动时,可以通过控制入射角来在CD峰值处任意实现从线性到圆形的输出偏振状态的动态调制。所提出的手性光栅超表面表现出独特的角度敏感可调谐CD光谱特性,使其成为高光谱和自旋选择性波前整形的理想选择,并在各种应用中拥有重要的前景,如光学安全,角度传感器,手性激光器,非线性滤波器,和其他有源手性光学器件。
    Dynamic control for a strong circular dichroism (CD) response is essential in engineering applications such as polarization manipulation, sensing, and imaging. Here, we propose and experimentally demonstrate a broadband tunable dual CD response via bound states in the continuum (BICs) in two-dimensional topologically protected metasurfaces composed of all-dielectric Si chiral grating structures that generate a pair of mixed and degenerated BIC mode and circular dichroic mode (CDM) as an additional degree of freedom in CD manipulation. It is found that a singular CD peak of nearly 100% at 1.6 μm can be achieved by CDM when BIC is hidden under normal incidence, while the CD peak can be split into two in which peak wavelengths can be precisely and linearly tuned over a bandwidth of 180 nm by the incident angle when the BIC mode is excited under oblique incidence. Additionally, dynamic modulation of output polarization states from linear to circular can be arbitrarily achieved at the split CD peaks by controlling the incident angle when asymmetry perturbations on chiral gratings are introduced due to the decoupling of various polarization states at Γ point by BIC to different positions in K space. The proposed chiral grating metasurface exhibits unique angle-sensitive tunable CD spectral characteristics, making it ideal for hyperspectral and spin-selective wavefront shaping, and holds significant promise in various applications such as optical security, angle sensors, chiral lasers, nonlinear filters, and other active chiral optical devices.
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  • 文章类型: Journal Article
    原子层沉积(ALD)是一种可以在原子基础上均匀沉积氧化锆的方法。在体内评估使用ALD沉积的氧化锆对钛植入物的影响。
    机械加工的钛植入物(MTI)用作对照。通过大砂砾和酸蚀刻(SA)喷砂处理的MTI和使用ALD用氧化锆沉积的MTI称为S和Z组,分别。每组制备12个植入物。六只兔子用作实验动物。为了评估植入物周围的成骨和骨细胞方面,进行了放射学和组织学分析.测量骨与植入物接触(BIC)比率并进行统计分析以评估骨整合能力。
    在显微CT分析中,在S组和Z组的植入物周围观察到更多的不透射线的骨组织。组织学观察发现,S组和Z组的皮质骨区植入物周围有更多和更致密的成熟骨组织。在髓腔区域还观察到许多新的和成熟的骨组织。对于BIC比率,S组和Z组皮质骨面积明显高于对照组(P<0.017),但是S组和Z组之间没有显着差异。
    使用ALD(Z组)在放射学和组织学上与MTIs(对照)相比,用氧化锆沉积的MTIs显示出更多的成熟骨形成和活化的骨细胞。Z组的BIC比率也显著高于对照组。在这项研究的局限性内,使用ALD在MTIs表面沉积氧化锆可以改善体内骨整合。
    UNASSIGNED: Atomic layer deposition (ALD) is a method that can deposit zirconia uniformly on an atomic basis. The effect of deposited zirconia on titanium implants using ALD was evaluated in vivo.
    UNASSIGNED: Machined titanium implants (MTIs) were used as the Control. MTIs treated by sandblasting with large grit and acid etching (SA) and MTIs deposited with zirconia using ALD are referred to as Groups S and Z, respectively. Twelve implants were prepared for each group. Six rabbits were used as experimental animals. To evaluate the osteogenesis and osteocyte aspects around the implants, radiological and histological analyses were performed. The bone-to-implant contact (BIC) ratio was measured and statistically analyzed to evaluate the osseointegration capabilities.
    UNASSIGNED: In the micro-CT analysis, more radiopaque bone tissues were observed around the implants in Groups S and Z. Histological observation found that Groups S and Z had more and denser mature bone tissues around the implants in the cortical bone area. Many new and mature bone tissues were also observed in the medullary cavity area. For the BIC ratio, Groups S and Z were significantly higher than the Control in the cortical bone area (P < 0.017), but there was no significant difference between Groups S and Z.
    UNASSIGNED: MTIs deposited with zirconia using ALD (Group Z) radiologically and histologically showed more mature bone formation and activated osteocytes compared with MTIs (Control). Group Z also had a significantly higher BIC ratio than the Control. Within the limitations of this study, depositing zirconia on the surface of MTIs using ALD can improve osseointegration in vivo.
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  • 文章类型: Journal Article
    我们考虑新开发的多项混合链接模型,用于具有DNA甲基化数据的高风险肠上皮化生(IM)研究。与通常用于分类响应的传统多项逻辑模型不同,混合链接模型允许我们为每个类别选择最合适的链接功能。我们表明,使用基于DNA甲基化数据的干细胞分裂总数(TNSC)的选定多项式混合链接模型(模型1)在十倍交叉验证的交叉熵损失方面优于传统逻辑模型,具有显着的p值8.12×10-4和6.94×10-5。根据我们选择的模型,TNSC效应在预测IM风险中的意义是合理的,p值小于10-6。当额外的协变量时,我们还选择最合适的混合链接模型(模型2和模型3),胃萎缩的状态,是可用的。当状态为负时,温和,或中度,我们推荐模型2;否则,我们更喜欢模型3。模型2和3都可以预测IM的风险明显优于模型1,这证明了胃萎缩的状态在预测IM的风险方面是有益的。
    We consider the newly developed multinomial mixed-link models for a high-risk intestinal metaplasia (IM) study with DNA methylation data. Different from the traditional multinomial logistic models commonly used for categorical responses, the mixed-link models allow us to select the most appropriate link function for each category. We show that the selected multinomial mixed-link model (Model 1) using the total number of stem cell divisions (TNSC) based on DNA methylation data outperforms the traditional logistic models in terms of cross-entropy loss from ten-fold cross-validations with significant p-values 8.12×10-4 and 6.94×10-5. Based on our selected model, the significance of TNSC\'s effect in predicting the risk of IM is justified with a p-value less than 10-6. We also select the most appropriate mixed-link models (Models 2 and 3) when an additional covariate, the status of gastric atrophy, is available. When the status is negative, mild, or moderate, we recommend Model 2; otherwise, we prefer Model 3. Both Models 2 and 3 can predict the risk of IM significantly better than Model 1, which justifies that the status of gastric atrophy is informative in predicting the risk of IM.
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  • 文章类型: Journal Article
    婴儿配方食品中禁用的添加剂严重影响婴儿的健康。太赫兹(THz)光谱具有丰富的指纹信息含量,在分析物检测中具有巨大的应用潜力。然而,对多种分析物的混合物的研究有限。在这项研究中,我们提出了一个裂环超表面,该表面支持连续体中的磁偶极子束下态(BIC)。通过打破对称性,可以产生具有高质量(Q)因子的准BIC。利用角度扫描策略,共振倾角的频率可以移动,从而绘制出可以反映分析物分子指纹的包络曲线。在婴儿配方奶粉中发现两种违禁添加剂,三聚氰胺和香兰素,可以按不同的比例识别。此外,引入了与色谱分析中的分辨率相似的度量,并计算为0.61,表明这两种添加剂可以同时检测。我们的研究为检测婴儿配方奶粉中的添加剂提供了一种新的解决方案。
    Prohibited additives in infant formula severely affect the health of infants. Terahertz (THz) spectroscopy has enormous application potential in analyte detection due to its rich fingerprint information content. However, there is limited research on the mixtures of multiple analytes. In this study, we propose a split ring metasurface that supports magnetic dipole bound states in the continuum (BIC). By breaking the symmetry, quasi-BIC with a high quality (Q) factor can be generated. Utilizing an angle-scanning strategy, the frequency of the resonance dip can be shifted, resulting in the plotting of an envelope curve which can reflect the molecular fingerprint of the analytes. Two prohibited additives found in infant formula, melamine and vanillin, can be identified in different proportions. Furthermore, a metric similar to the resolution in chromatographic analysis is introduced and calculated to be 0.61, indicating that these two additives can be detected simultaneously. Our research provides a new solution for detecting additives in infant formula.
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  • 文章类型: Journal Article
    目的:为了减少健康不平等,重要的是要确定受特权或不利影响的个体特征的交叉点。最近发表了不同的建议。一种方法(1)考虑具有一阶和所有二阶效应的模型,另一种方法(2)考虑基于多个协变量的分层;两者都对连续协变量进行分类。进行了模拟研究,以审查两种方法关于识别显示真实差异的交叉点,假阳性结果率,与根据贝叶斯信息标准(BE-BIC)结合样条的已建立的后向变量消除方法(3)相比,以及对独立数据的泛化性。
    方法:R软件已用于模拟协变量年龄,性别,身体质量指数,教育,和糖尿病,使用多元线性回归检查它们与骨质疏松症持续衰弱评分的关联。在设置1中,没有一个协变量与脆弱分数相关,即,只有噪声存在于数据中。在设置2中,协变量年龄,性别,他们的互动与脆弱分数有关,这样,只有55岁以上的女性才形成与虚弱评分增加相关的交叉点。在不同的样本量(N=200-3000)和信噪比(SNR,0.5-4)在1000次重复中。对于模型评估,使用引导重采样。这些模型在内部学习数据中拟合,然后用于预测内部验证数据中的结果。使用均方误差(MSE)进行比较,并计算假阳性发现的频率。
    结果:在设置1中,方法1和2在所有样本量的90%以上的模拟中产生了虚假效应。在较小的样本量中,方法3(BE-BIC)选择了36.5%的正确模型,在89.8%的较大样本量中,虚假效应的数量总是较少。与方法3相比,方法1和2的独立数据中的MSE通常更高。在设置2中,方法1最频繁地选择正确的相互作用,但经常显示虚假效应(>75%)。在所有样本量和SNR中,方法3产生的虚假结果最少,并且在独立数据中MSE最低。
    结论:连续协变量的分类不利于交叉性研究。由于高且不受限制的模型复杂性,此类方法易于产生虚假效应,并且通常缺乏可解释性。方法3(BE-BIC)对虚假发现要稳健得多,对独立数据表现出更好的泛化性,并且可以与大多数统计软件一起使用。对于交叉性研究,我们认为最重要的是描述交叉点之间的相关差异,并避免不可重复和虚假的发现。
    OBJECTIVE: To reduce health inequities, it is important to identify intersections in characteristics of individuals subject to privilege or disadvantage. Different proposals for that have recently been published. One approach (1) considers models specified with first- and all second-order effects and another (2) the stratification based on multiple covariates; both categorize continuous covariates. A simulation study was conducted in order to review both methods with regard to identification of intersections showing true differences, rate of false-positive results, and generalizability to independent data compared to an established approach (3) of backward variable elimination according to Bayesian information criterion (BE-BIC) combined with splines.
    METHODS: R software has been used to simulate the covariates age, sex, body mass index, education, and diabetes to examine their association with a continuous frailty score for osteoporosis using multiple linear regression. In setting 1, none of the covariates was associated with the frailty score, that is, only noise is present in the data. In setting 2, the covariates age, sex, and their interaction were associated with the frailty score, such that only females above 55 years formed an intersection associated with an increased frailty score. All approaches were compared under varying sample sizes (N = 200-3000) and signal-to-noise ratios (SNRs, 0.5-4) in 1000 replications. For model evaluation, bootstrap resampling was used. The models were fitted in internal learning data and then used to predict outcomes in the internal validation data. The mean squared error (MSE) was used for comparison and the frequency of false-positive findings calculated.
    RESULTS: In setting 1, approaches 1 and 2 generated spurious effects in more than 90% of simulations across all sample sizes. In a smaller sample size, approach 3 (BE-BIC) selected 36.5% of the correct model, in larger sample size in 89.8% and always had a lower number of spurious effects. MSE in independent data was generally higher for approaches 1 and 2 when compared to 3. In setting 2, approach 1 selected most frequently the correct interaction but frequently showed spurious effects (>75%). Across all sample sizes and SNR, approach 3 generated least often spurious results and had lowest MSE in independent data.
    CONCLUSIONS: Categorization of continuous covariates is detrimental to studies on intersectionality. Due to high and unrestricted model complexity, such approaches are prone to spurious effects and often lack interpretability. Approach 3 (BE-BIC) is considerably more robust against spurious findings, showed better generalizability to independent data, and can be used with most statistical software. For intersectionality research, we consider it most important to describe relevant differences between intersections and to avoid nonreproducible and spurious findings.
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  • 文章类型: Journal Article
    我们提出了一种新的同时变量选择和估计程序,其高斯无缝-L0$${L}_0$$(GSELO)惩罚Cox比例风险模型和加性风险模型。GSELO过程显示出通过从最佳子集选择(BSS)和正则化两者中获取强度来改进现有变量选择方法的良好潜力。此外,我们开发了一个迭代算法来实现所提出的过程在计算有效的方式。理论上,我们建立了算法的收敛性和所提出的过程的渐近理论性质。由于参数调整对GSELO程序的性能至关重要,我们还为GSELO程序提出了扩展的贝叶斯信息标准(EBIC)参数选择器。模拟和真实数据研究已经证明了所提出的方法相对于几种最先进的方法的预测性能和有效性。
    We propose a new simultaneous variable selection and estimation procedure with the Gaussian seamless- L 0 $$ {L}_0 $$ (GSELO) penalty for Cox proportional hazard model and additive hazards model. The GSELO procedure shows good potential to improve the existing variable selection methods by taking strength from both best subset selection (BSS) and regularization. In addition, we develop an iterative algorithm to implement the proposed procedure in a computationally efficient way. Theoretically, we establish the convergence properties of the algorithm and asymptotic theoretical properties of the proposed procedure. Since parameter tuning is crucial to the performance of the GSELO procedure, we also propose an extended Bayesian information criteria (EBIC) parameter selector for the GSELO procedure. Simulated and real data studies have demonstrated the prediction performance and effectiveness of the proposed method over several state-of-the-art methods.
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  • 文章类型: Journal Article
    在统计实践中,为了合并估计和模型选择问题而拟合惩罚模型已变得司空见惯。在为此可以利用的各种正规化策略中,使用l0范数来惩罚参数估计是最艰巨的模型拟合任务。事实上,这种特殊的策略需要最终用户解决非凸NP难优化问题,而不管底层数据模型。出于这个原因,l0范数作为正则化策略的使用被严重低估了。为了消除这种困难,制定了解决统计界普遍可获得的此类问题的战略。该方法可用于解决非常广泛的模型中的l0规范惩罚问题,可以使用现有软件实现,并且计算效率很高。通过深入的数值实验以及使用它来分析几个原型数据集,证明了该方法的性能。
    Fitting penalized models for the purpose of merging the estimation and model selection problem has become commonplace in statistical practice. Of the various regularization strategies that can be leveraged to this end, the use of the l0 norm to penalize parameter estimation poses the most daunting model fitting task. In fact, this particular strategy requires an end user to solve a non-convex NP-hard optimization problem irregardless of the underlying data model. For this reason, the use of the l0 norm as a regularization strategy has been woefully under utilized. To obviate this difficulty, a strategy to solve such problems that is generally accessible by the statistical community is developed. The approach can be adopted to solve l0 norm penalized problems across a very broad class of models, can be implemented using existing software, and is computationally efficient. The performance of the method is demonstrated through in-depth numerical experiments and through using it to analyze several prototypical data sets.
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  • 文章类型: Journal Article
    等离子体共振可以大大增强二维范德华材料的光-物质相互作用。然而,等离子体共振的品质因数是有限的。这里,我们证明了连续体中的等离子体准束缚态(准BIC),由金纳米棒对组成。通过控制纳米棒的旋转角度,可以调谐等离子体激元BIC模式的品质因数。模拟结果表明,等离子体激元BIC结合了来自BIC效应的高质量因子和来自等离子体激元共振的小模式体积的优点。实验结果表明,所设计的等离子体BIC模式在1250nm左右的波长下表现出高于15的品质因数。通过将等离子体结合态结构与单层二碲化钼(MoTe2)整合,PL光谱中MoTe2的激子发射分为两种激子-极化子模式,这归因于高Q因子和BIC模式与MoTe2激子之间的强相互作用。
    Plasmon resonances can greatly enhance light-matter interactions of two-dimensional van der Waals materials. However, the quality factor of plasmonic resonances is limited. Here, we demonstrate a plasmonic quasi-bound state in the continuum (quasi-BIC), which is composed of gold nanorod pairs. Through controlling the rotation angle of the nanorods, the quality factor of the plasmonic BIC mode can be tuned. Simulation results show that the plasmonic BIC combines the advantages of high-quality factor from the BIC effect and small mode volume from plasmonic resonance. Experiment results show that the designed plasmonic BIC mode exhibits a quality factor higher than 15 at the wavelength of around 1250 nm. Through integrating the plasmonic bound state structure with monolayer molybdenum ditelluride (MoTe2), the exciton emission of MoTe2 in the PL spectrum split into two exciton-polariton modes, which is attributed to the high Q factor and strong interaction between the BIC mode and excitons of MoTe2.
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  • 文章类型: Journal Article
    背景:COVID-19导致的住院时间(LOHS)造成了经济负担,医疗服务系统的成本以及患者和卫生工作者的高心理负担。这项研究的目的是采用基于线性回归模型的贝叶斯模型平均(BMA),并确定COVID-19LOHS的预测因子。
    方法:在这项历史队列研究中,从5100名在医院数据库注册的COVID-19患者中,4996名患者有资格进入研究。数据包括人口统计,临床,生物标志物,和LOHS。影响LOHS的因素在六个模型中进行了拟合,包括逐步方法,AIC,经典线性回归模型中的BIC,使用奥卡姆窗口和马尔可夫链蒙特卡罗(MCMC)方法的两个BMA,和GBDT算法,一种新的机器学习方法。
    结果:平均住院时间为6.7±5.7天。在拟合经典线性模型时,逐步法和AIC法(R2=0.168,调整后的R2=0.165)均优于BIC法(R2=0.160,调整后的R2=0.158)。在适应BMA时,Occam的Window模型的性能优于MCMC,R2=0.174。值R2=0.64的GBDT方法在测试数据集中的表现比BMA差,但在训练数据集中没有表现。基于六个拟合模型,在ICU住院,呼吸窘迫,年龄,糖尿病,CRP,PO2,WBC,AST,BUN,NLR与预测COVID-19的LOHS显著相关。
    结论:使用Occam\'sWindow方法的BMA在预测测试数据集中的LOHS影响因素方面比其他模型具有更好的拟合和性能。
    The length of hospital stay (LOHS) caused by COVID-19 has imposed a financial burden, and cost on the healthcare service system and a high psychological burden on patients and health workers. The purpose of this study is to adopt the Bayesian model averaging (BMA) based on linear regression models and to determine the predictors of the LOHS of COVID-19.
    In this historical cohort study, from 5100 COVID-19 patients who had registered in the hospital database, 4996 patients were eligible to enter the study. The data included demographic, clinical, biomarkers, and LOHS. Factors affecting the LOHS were fitted in six models, including the stepwise method, AIC, BIC in classical linear regression models, two BMA using Occam\'s Window and Markov Chain Monte Carlo (MCMC) methods, and GBDT algorithm, a new method of machine learning.
    The average length of hospitalization was 6.7 ± 5.7 days. In fitting classical linear models, both stepwise and AIC methods (R 2 = 0.168 and adjusted R 2 = 0.165) performed better than BIC (R 2 = 0.160 and adjusted = 0.158). In fitting the BMA, Occam\'s Window model has performed better than MCMC with R 2 = 0.174. The GBDT method with the value of R 2 = 0.64, has performed worse than the BMA in the testing dataset but not in the training dataset. Based on the six fitted models, hospitalized in ICU, respiratory distress, age, diabetes, CRP, PO2, WBC, AST, BUN, and NLR were associated significantly with predicting LOHS of COVID-19.
    The BMA with Occam\'s Window method has a better fit and better performance in predicting affecting factors on the LOHS in the testing dataset than other models.
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