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Light-induced photonic systems are rare in nature and usually lack a full color response in artificial systems. Herein, we first report a near-infrared (NIR) light controlled optical hydrogel; its ...

Almost two decades ago strain and strain rate imaging were proposed as a new, potentially more sensitive modality for quantifying both regional and global myocardial function. Until now, however, strain and strain rate imaging have been slow to be incorporated into everyday clinical practice. More recently, two dimensional strain has been claimed as of greater clinical utility, given that it is angle independent, with improved feasibility and reproducibility as compared to tissue Doppler strain. Nevertheless, speckle tracking strain is reliant on 2D image quality and frame rates. Three dimensional speckle tracking could eliminate the problem of through-plane motion inherent in 2D imaging, but 3D strain is currently limited by low frame rates. Another limitation of strain imaging is that the results are dependent on the ultrasound machine on which analyses are performed, with variability in measurements between different vendors. Despite the diagnostic and prognostic advantages of 2D strain, there is a lack of specific therapeutic interventions based on strain and a paucity of long-term large-scale randomized trial evidence on cardiovascular outcomes. After overabundant literature the same definition of normal cut-off values is controversial and not univocal. Further studies are needed, involving both manufacturers and medical professionals, on the additive contribution, possibly different case by case, of interfering and artifactual factors, aside from myocardial function per se. These artifactual determinants and motion artifacts components could be dominant in individual cases and should always be taken into account in the clinical decision making process in a single case.

Color materials utilizing physical phenomena such as scattering, diffraction, and interference of light have drawn attention as alternatives to organic dyes that fade by light and some inor...

It is easy for chemical pigments produced from organic chemicals to disappear when exposed to light over time. Recently, structurally colored pigments produced by materials with high indices of ref...

Assessment of diaphragmatic function has been well described in the intensive care setting as well as in emergency medicine and pediatrics. Conventional M-mode evaluation of diaphragmatic excursion is frequently associated with over and under-estimations of diaphragmatic excursion. Angle-independent M-mode allows free rotation and movement of the analysis line to obtain M-mode images in a direction that more accurately reflects diaphragmatic excursion. In order to provide a standardized approach to the evaluation of diaphragmatic excursion with angle-independent M-mode, we propose a landmark-based approach utilizing the spine in order to target the same diaphragmatic segment consistently throughout the diaphragmatic analysis. While the proposed approach is not intended to replace current methods, it may improve accuracy and inter-rater reliability. The relevant background, as well as three patient cases, are presented demonstrating the use of a landmark-based approach in the emergency department. Angle-independent M-mode may provide a more accurate and consistent evaluation of diaphragmatic excursion, an examination that can be used to guide clinical care and anticipate outcomes.

Publisher Copyright: © 2020 IEEE. The difference co-array is crucial in determining the number of resolvable sources in direction-of-arrival (DoA) estimation. This virtual array of pairwise sensor position differences enables sparse arrays to identify vastly more sources than sensors. However, the idealized assumptions giving rise to the co-array, such as isolated omnidirectional gain patterns, may not hold in practice. Consequently, the applicability of the co-array model to real-world arrays needs to be investigated thoroughly. In this work, we consider a general class of angle-independent departures from the ideal model caused by nonideal sensors or compression of the array measurements. We study the impact of these nonidealities on DoA estimation using co-array MUSIC, assuming that the array is calibrated and that an infinite number of snapshots is available. We establish that proper use of the calibration data enables unbiased DoA estimation of more sources than sensors. Nonidealities may nevertheless cause subspace swap at low SNR.

In polarization holography, the polarization information is recorded in the photopolymer material by interference, and the polarization state of the reconstructed wave can be calculated accurately by tensor method. Based on the guidance of tensor theory, this paper systematically analyzes the method of faithful reconstruction under any interference angle independent of exposure energy, and gives experimental verification under the condition of 40° interference angle. This conclusion is helpful to broaden our understanding of polarization holography based on tensor theory, and can be applied to the research of polarization multiplexing multi-channel holography.

Narrow bandpass filters are essential optical components for multispectral/ hyperspectral cameras. This paper presents a narrow bandpass filter that requires single stage fabrication for all the bands towards developing single sensor based multispectral cameras.

In this contribution, we present the direct comparison between Ophir Pyrocam IV and Terasense Tera-1024 cameras used for imaging of terahertz (THz) and sub-THz signals. We compare general properties, such as frequency dependent and polarisation dependent sensitivity, angle dependent sensitivity essential for holographic and noncollinear interferometric measurements, and draw a conclusion about the most suitable camera for the discussed imaging approaches. Both cameras show acceptable performance and sensitivity at imaging both 0.14 THz and 0.3 THz signals. The Terasense camera, expectedly, shows stronger polarisation dependent properties, however, is significantly more angle independent, showing an acceptable performance at all tested incident angles up to 50 degrees. At the same time, although the angle dependence is stronger for the Ophir camera, it has smaller pixel pitch and more extended post-processing features, thus making it somewhat better suited for noncollinear interferometric and holographic sub THz imaging.

We show through rigorous calculation that optical binding can organize hyperbolic metamaterial slabs into one-dimensional photonic hypercrystals. It was reported that a photonic hypercrystal can possess an angle-independent band gap and blueshifting and redshifting band gaps. We find that an angle-independent band gap could lead to angle-independent optical binding, where light can organize a collection of hyperbolic slabs into one mechanically stable photonic hypercrystal, irrespective of the angle of incidence of the incident plane wave. We call such a phenomenon incident angle-independent optical binding. In addition, the evolution of the lattice constants of the self-organized photonic hypercrystals with blueshifting and redshifting band gaps is also investigated.

Extant weevils exhibit a remarkable colour palette that ranges from muted monochromatic tones to rainbow-like iridescence, with the most vibrant colours produced by three-dimensional photonic nanostructures housed within cuticular scales. Although the optical properties of these nanostructures are well understood, their evolutionary history is not fully resolved, in part due to a poor knowledge of their fossil record. Here, we report three-dimensional photonic nanostructures preserved in brightly coloured scales of two weevils, belonging to the genusPhyllobiusorPolydrusus, from the Pleistocene (16–10 ka) of Switzerland. The scales display vibrant blue, green and yellow hues that resemble those of extantPhyllobius/Polydrusus. Scanning electron microscopy and small-angle X-ray scattering analyses reveal that the subfossil scales possess a single-diamond photonic crystal nanostructure. In extantPhyllobius/Polydrusus, the near-angle-independent blue and green hues function primarily in crypsis. The preservation of far-field, angle-independent structural colours in the Swiss subfossil weevils and their likely function in substrate matching confirm the importance of investigating fossil and subfossil photonic nanostructures to understand the evolutionary origins and diversification of colours and associated behaviours (e.g. crypsis) in insects.

In this work, we report a facile way to fabricate fluorescent spherical photonic crystals (SPCs) microspheres for the first time. The SPCs microspheres immobilizing Photonic Bandgap (PBG) structure into a hydrogel framework, which can be used to uptake nanosized CdTe NCs particles based on their reversible volume phase transition behavior. Moreover, the resultant SPCs microspheres can not only monitor surrounding humidity, but also exhibit well integration of fluorescence and PBG color in a single structure. More interestingly, the photoluminescence (PL) spectra of fluorescent SPCs microspheres are angle-independent on the curved surface which would open a novel insight into the fabrication of multifunctional optical devices based on PBG and PL functionalities.

The hues of blue birds come from constructive interference, but scattering and refraction also matter.

In nature, many living organisms exhibit low-angle-dependent or even angle-independent structural colors for wide viewing angle, such as the blue skin of mandrill, feather of blue bird and shell of longhorn beetle, etc. To mimic these structural colors, based on periodic semicircular micro-grooved (PSMG) substrate, silica colloidal photonic crystals provide anisotropic angle-independent structural colors. The PSMG photonic crystals were fabricated by self-assembling monodispersed silica nanoparticles on a micro-grooved template, which can be easily prepared in large scale by a hot embossing method, and no additional materials are needed in the whole preparation process. The PSMG photonic crystals exhibit identical structural colors around the groove axis, whereas it is angle-dependent along the groove axis. In addition, this PSMG surface of photonic crystal also leads to color separation effect and monocolor polarization conversion. This system provides a facile and scalable means to prepare anisotropically angle-independent colloidal photonic crystal, which is considered important in applications in the field of anti-counterfeiting or the manufacture of monochromatic light reflector with wide viewing angles and other novel optical devices.

Whiteness, although frequently apparent on the wings, legs, antennae, or bodies of many species of moths and butterflies, along with other colors and shades, has often escaped our attention. Here, we investigate the nanostructure and microstructure of white spots on the wings of Carystoides escalantei, a dusk-active and shade-inhabiting Costa Rican rain forest butterfly (Hesperiidae). On both males and females, two types of whiteness occur: angle dependent (dull or bright) and angle independent, which differ in the microstructure, orientation, and associated properties of their scales. Some spots on the male wings are absent from the female wings. Whether the angle-dependent whiteness is bright or dull depends on the observation directions. The angle-dependent scales also show enhanced retro-reflection. We speculate that the biological functions and evolution of Carystoides spot patterns, scale structures, and their varying whiteness are adaptations to butterfly’s low light habitat and to airflow experienced on the wing base vs. wing tip.

Strain analysis allows for global and regional analysis of myocardial function and has been shown to be an independent predictor of outcomes after cardiac surgery. Strain imaging offers advantages over traditional EF measurements in that it is relatively angle independent, it is less dependent upon loading conditions, it is reproducible, it does not rely on geometric assumptions, and it can detect subclinical systolic dysfunction. Limitations of strain analysis include high temporal resolution requirements, a strong dependence on image quality, and inter-vendor variability. In addition, there is a paucity of data on the intraoperative applications of strain. The ASE has defined a global longitudinal strain of -20% measured by transthoracic echocardiography to be considered normal, with less negative values considered abnormal. Presently, there are no published guidelines on the normal values of strain with transesophageal echocardiography (TEE). However, multiple studies have shown that a reduction in intraoperative strain assessed with TEE has been shown to be an independent predictor of complications during cardiac surgery. Accordingly, further incorporation of intraoperative strain analysis with TEE could aid in prognostication for patients undergoing cardiac surgery. As perioperative strain analysis continues to advance, an understanding of these concepts is imperative for perioperative echocardiographers. It is the authors' goal to show that strain imaging can provide a reliable and objective measure that can be performed in real time to aid in decision-making and perioperative risk stratification.

Structural colors are in increasing demand in many fields such as color displays, sensor devices, and anti-counterfeiting labels. Herein, large-scale and angle-independent structural colors were constructed from polydopamine (PDA) coatings with a high refractive index and uniformity. This strategy can be utilized to facilely fabricate various color patterns. These structural colors also display high solvent resistance and excellent universality to a series of substrates. Moreover, stimuli-responsive structural colors can be easily synthesized via the co-deposition of PDA with poly(N-isopropylacryl-amide). To the best of our knowledge, this is the first time that structural colors from PDA-based coatings have been reported.

Objectives Sonographic assessment of diaphragm displacement has conventionally been conducted with M-mode sonography via an anterior subcostal approach. This method is subject to measurement errors when diaphragm displacement is not in line with the M-mode plane. We aimed to compare measurements obtained by offline angle-independent (anatomic) M-mode sonography with conventional M-mode sonography. Methods Fifty healthy adults were imaged with conventional and angle-independent M-mode sonography of the bilateral hemidiaphragms at 60% maximal inspiratory capacity using an inspiratory spirometer. Results Left hemidiaphragm displacement was successfully imaged by conventional M-mode sonography in only 70% (n = 35), as lung expansion obscured imaging, whereas 92% (n = 46) were assessable by angle-independent M-mode sonography. All right hemidiaphragm displacement could be assessed. Conventional M-mode results were higher than angle-independent M-mode results on the right (mean ± SD, 4.9 ± 1.4 versus 4.6 ± 1.2 cm, respectively; P= .003) and left (5.4 ± 1.3 versus 4.6 ± 1.0 cm; P < .001). Displacement values were different for right versus left hemidiaphragms on conventional M-mode sonography (mean difference, 0.6 ± 0.2 cm; P = .005), with only mild agreement (R2 = 0.35; P < .001). There was no laterality seen in the diaphragm displacement on angle-independent M-mode sonography (mean difference, 0.1 ± 0.1 cm; P = .47), with good agreement (R2 = 0.76; P < .001). Conclusions Angle-independent M-mode sonography leads to better visualization and assessment of the left hemidiaphragm. It records lower displacement than conventional M-mode sonography in the bilateral diaphragms, likely because of fewer orientation and translation errors. Future study is indicated to assess the clinical utility of angle-independent M-mode sonography in a population with diaphragm dysfunction.

Structural colors with anti-photo bleaching character have attracted great attentions in energy-saving reflective displaying. However, the brilliant color will disappear once the film is wet, due to the decreased refractive index contrast. Generally, hydrophobic colored films are produced from hydrophobic nanoparticles, three-dimension ordered macroporous structures or spray coating of hydrophobic treated silica NPs. But the process of the three-dimension ordered macroporous structures is time consuming and this ordered array will lead to iridescent colors. Besides, it has been recognized that some fluorochemicals have potential risks to human health and environment. In this work, we report the angle-independent structurally colored films with a superhydrophobic property fabricated by spray coating of SiO2 NPs and PDMS. The as-prepared films exhibit a high contact angle (∼165°) and a low roll-off angle (

Employing a silver nano semi-ellipsoid nanoarray with high symmetry into applications in plasmonic color printing, we fulfill printing images with colors independent of observing angles. Also, by decreasing the period of a nano semi-ellipsoid array into deep-subwavelength scales, we obtain high reflectivity over 50%, promising high efficiency for imaging generations. A facile technique based on the transfer of anodized aluminum oxide template is developed to fabricate the silver nano semi-ellipsoid nanoarray, realizing plasmonic color printing with features of low cost, scalable, full color and high flexibility. Our approach provides a feasible way to address the angle-dependent issue in the previous practice of plasmonic color printing, and boosts this field on its way to real-world commercial applications.

Combining dip coating of colloidal particles on a substrate with standard microelectronics fabrication techniques creates nanostructures with tunable structural color suited for a variety of applications.

We derive a general condition for angle-independent bianisotropic nongyrotropic metasurfaces and present two applications corresponding to particular cases: an angle-independent absorber/amplifier and an angle-independent spatial gyrator.

Left ventricular (LV) dysfunction increases the risk for serious post-operative complications. Accurate assessment of LV wall motion is necessary to guide anesthetic management; however, traditional measures have a high degree of inter- and intra-observer variability. Myocardial deformation as measured by strain and strain rates is improving the diagnostic and prognostic utility of echocardiography to determine LV function in patients with cardiovascular disease. Strain can be measured using tissue Doppler and speckle tracking imaging from two-dimensional or three-dimensional echocardiography using various online and offline software packages. Tissue Doppler strain analysis provides excellent temporal resolution but is limited by the imaging angle of insonation. Speckle tracking strain imaging is angle independent and now the more commonly used modality. Strain has been demonstrated to guide therapy, monitor disease progression in various pathologic states, and is emerging as a strong predictor of clinical outcomes.

A smart window is fabricated from a composite consisting of elastomeric poly(dimethylsiloxane) embedded with a thin layer of quasi-amorphous silica nanoparticles. The smart window can be switched from the initial highly transparent state to opaqueness and displays angle-independent structural color via mechanical stretching. The switchable optical property can be fully recovered after 1000 stretching/releasing cycles.

Arterial stiffness is a strong indicator of atherosclerosis, and can be evaluated by computing the arterial strain in the carotid artery using ultrasound elastography. Researchers have used axial strain to visualize the radial motion in the longitudinal plane of the carotid artery. However, axial strains can be influenced by the geometry of the vessel (Fig. 1 a, b), and thus could limit the scope of vascular elastography in the clinic. In this study we hypothesize that principal strain elastograms computed using compounded plane wave (CPW) imaging could reliably estimate angle-independent vascular strains in the carotid artery.

Incorporating different data processing methods, Optical coherence tomography (OCT) has the ability for high-resolution micro-angiography and quantitative flow velocity measurement. However, OCT micro-angiography cannot provide quantitative measurement of flow velocity, and the velocity measurement based on Doppler OCT requires the determination of Doppler angles, which are difficult for whole vascular network. In this study, we report a relative standard deviation OCT (RSD-OCT) for the mapping of the flow velocity in a vascular network without the calculation of Doppler angle. From the theoretical analysis and experimental validation, the RSD-OCT is angle-independent and can quantify the flow velocity conveniently after a calibration.

The effect of chiral angle independent from diameter on tensile behavior of single-walled carbon nanotubes (SWCNTs) is studied. Two methods in finite element continuum mechanics modeling of SWCNTs are used. The role of chiral angle and diameter are investigated independently on linear and nonlinear tensile behavior of SWCNTs by modeling several types of nanotubes. Nonlinear tensile behavior is more influenced by chiral angle than the linear Young's modulus of SWCNTs. On the other hand, the effect of diameter is found to be more obvious on Young's modulus than nonlinear tensile behavior of SWCNTs.

Background: The plunging tip is defined as a nasal deformity where the nasal tip descends or “plunges” during smiling. Objective: The authors prospectively measure a series of 25 patients with a focus on the anatomic changes of the nose before and after the patient smiles. Methods: Twenty-five women who presented for cosmetic primary rhinoplasty and complained of a plunging tip were included in the study. Three angles were measured on lateral view (tip angle, nasolabial angle, and columella inclination angle), along with changes in tip, subnasale, and alar crease. The Simon tip rotation angle (STRA) measured tip position in relation to the static tragus. The alar rim angle measured the angle of the alar rim at the nostril. Changes in static and smiling positions were compared. Results: Tip, nasolabial, and the columella inclination angles decreased between static and smiling positions by 10.9, 11.8, and 11.9 degrees, respectively. Tip position dropped by 0.9 mm, while the subnasale and alar crease junction elevated by 1.3 and 3.7 mm, respectively. The STRA, an angle independent of alar base movement, decreased by less than 1 degree. The alar rim angle increased by 9.9 degrees. Conclusions: Our data demonstrate that the nasal tip changes its position less than 1 mm with a full smile. The concept of a “plunging tip” is an optical illusion. In reality, the alar crease and subnasale elevate and the alar rim straightens, while the tip position changes minimally. Objectively, the tip moves less than 1 mm and less than 1 degree using the STRA. Level of Evidence: 3 ![Graphic][1] [1]: /embed/inline-graphic-1.gif

Light-induced saturation changes in the angle-independent structural coloration of a colloidal amorphous array mainly composed of submicron-sized fine spherical silica particles including a tiny amount of titanium oxide nanoparticles were investigated using a photoelectrochemical reaction of the Ag/Ag+ system, which can exhibit a change in the brightness of the black color.

Nanostructures of indium tin oxide (NSITO) deposited using glancing angle deposition (GLAD) technique are used to enhance the outcoupling efficiency of blue and green OLEDs. The enhancement was found to be angle independent. The efficiency of device has increased by about 2.1 times by the use of NSITO at glass/air interface and ITO/glass interface. Similarly nano-phosphor particles were used to recover the glass modes by depositing them on the backside of the substrates. Both these methods were found to be effective for outcoupling efficiency enhancement.

Objective Quantification of fetal right ventricular (RV) function by 2D-echocardiography is challenging. Velocity vector imaging (VVI) is an angle independent speckle tracking technique that assesses regional myocardial mechanics. Alteration in the deformation of the fetal RV in hypoplastic left heart syndrome (HLHS) is unknown. This study aimed to evaluate the regional mechanics of the fetal RV in HLHS. Methods We retrospectively analyzed HLHS fetuses imaged at our center. Velocity, strain and strain rate were obtained using VVI. Global and regional parameters of RV deformation were compared between HLHS fetuses and gestational age matched controls. Results A total of 30 HLHS fetuses and 30 gestational age matched controls were analyzed. The mean gestational age was 30.5 ±3.5 weeks. Global myocardial strain was significantly decreased in HLHS RVs compared to controls (−1.9% vs. -4.1%, p = 0.003). The volume of the hypoplastic left ventricle did not affect RV deformation in HLHS. Conclusions Compared to controls, the RV in HLHS fetuses has decreased systolic strain. Prenatal abnormalities in RV myocardial deformation may be responsible for inefficient cardiac performance and output. RV myocardial performance in HLHS can be measured prenatally and may be predictive of post-natal RV dysfunction. © 2012 John Wiley & Sons, Ltd.

BACKGROUND: Speckle tracking echocardiography (STE) is an angle independent method with high temporal resolution, which offers quantification of regional left ventricular (LV) wall motion. We studi ...