DigiLens (United States)

Abstract Background Bronchopulmonary dysplasia (BPD) is one of the most common and serious sequelae of prematurity. Prompt diagnosis using prediction tools is crucial for early intervention and prevention of further adverse effects. This study aims to develop a machine learning-based BPD-free survival prediction tool based on the concept of the developmental origin of BPD. Methods Datasets comprising perinatal factors and early postnatal respiratory support were used for initial model development, followed by combining the two models into a final ensemble model using logistic regression. Simulation of clinical scenarios was performed. Results Data from 689 infants were included in the study. We randomly selected 80% of which was used for model development and used the remainder 20% for validation. The performance of the final model was assessed by receiver operating characteristics which showed 0.921 (95% CI: 0.899–0.943) and 0.899 (95% CI: 0.848–0.949) for the training and the validation datasets, respectively. Simulation data suggests that extubating to CPAP is superior to NIPPV in BPD-free survival. Additionally, successful extubation may be defined as no reintubation for 9 days following initial extubation. Conclusions Machine learning-based BPD prediction based on perinatal features and respiratory data may have clinical applicability to promote early targeted intervention in high-risk infants.

As urban areas continue to expand and play a critical role as both contributors to climate change and hotspots of vulnerability to its effects, cities have become battlegrounds for climate change adaptation and mitigation. Large amounts of earth observations from space have been collected over the last five decades and while most of the measurements have not been designed specifically for monitoring urban areas, an increasing number of these observations is being used for understanding the growth rates of cities and their environmental impacts. Here we reviewed the existing tools available from satellite remote sensing to study urban contribution to climate change, which could be used for monitoring the progress of climate change mitigation strategies at the city level. We described earth observations that are suitable for measuring and monitoring urban population, extent, and structure; urban emissions of greenhouse gases and other air pollutants; urban energy consumption; and extent, intensity, and effects on surrounding regions, including nearby water bodies, of urban heat islands. We compared the observations available and obtainable from space with the measurements desirable for monitoring. Despite considerable progress in monitoring urban extent, structure, heat island intensity, and air pollution from space, many limitations and uncertainties still need to be resolved. We emphasize that some important variables, such as population density and urban energy consumption, cannot be suitably measured from space with available observations.

Wide field of view color waveguide display reference designs for low-cost consumer AR displays using high index modulation photopolymer and liquid crystal material for providing compact wide-angle, displays are presented.

DigiLens Switchable Bragg Grating (SBG) waveguide technology enables compact color HUDs for consumer transportation AR applications with a wide field of view, high brightness fabricated using a low-cost printing process.

DigiLens’s Switchable Bragg Grating (SBG) waveguides enable switchable, tunable and digitally reconfigurable color waveguide displays with a field of view, brightness and form factor surpassing those of competing technologies. DigiLens waveguides can be laminated to integrate multiple optical functions into a thin transparent device. DigiLens waveguide gratings are printed into a proprietary polymer and liquid crystal mixture that can provide any required combination of diffraction efficiency and angular bandwidth in a thin waveguide with high transparency and very low haze. The waveguide combines two key components: an image generation module, essentially a pico projector, and a holographic waveguide for propagating and expanding the image vertically and horizontally. Color is provided by a stack of monochrome waveguides each capable of addressing the entire field of view, incorporating an input rolled K-vector grating, a fold grating, and an output grating. Rolling the K-vectors expands the effective angular bandwidth of the waveguide. Fold gratings enable two-dimensional beam expansion in a single waveguide layer, which translates into lower manufacturing cost, reduced haze, and improved image brightness. The design of these complex SBGs is complicated by their birefringent properties, taking the design of DigiLens waveguides well beyond the frontiers of established ray-tracing codes. Our paper summarizes the key features of DigiLens waveguide technology and discusses our optical design methodology, with examples from DigiLens’s current waveguide HUD products.

This work presents the use of a tunable-focus thermo-responsive hydrogel based liquid lens in combination with an objective lens to achieve remote axial focusing in a conventional microscopy. The goal of this design is to eliminate image distortion due to sample vibrations caused by mechanical stage scanning. This approach reduces the mechanical complexity and power consumption due to the use of electrically tunable lenses while achieving a two-fold increase in the axial scanning range. The merits of the proposed design were demonstrated by characterizing a customized microscope system over a scanning range of 1700 μm. A lateral resolution of 2 μm was obtained consistently throughout the scanning range. Healthy Spodoptera frugiperda Sf21 insect cells imaging was used to verify the depth scanning ability and the resolution of our remote focusing microscope system.

Esquireite, BaSi_6O_(13)·7H_2O, is a new mineral from the Esquire #1 claim along Rush Creek, eastern Fresno County, California, USA, and a Ba-silicate lens on the NW slope of Trumbull Peak, Mariposa County, California, USA. Esquireite is a low-temperature hydrothermal alteration product of sanbornite and is found on surfaces of sanbornite. The mineral occurs as colorless rectangular blades, elongated and striated parallel to [010] and flattened on {001}. The streak is white, the luster is vitreous to pearly, and the crystals are transparent. The Mohs hardness is about 2. The tenacity is somewhat flexible, but not elastic, with brittle failure. The fracture is irregular and there are two cleavages: perfect on {001} and fair on {100}. The measured and calculated densities are 2.18(2) g/cm^3 and 2.237 g/cm^3, respectively. Esquireite is biaxial (+), with α 1.477(1), β 1.481(1), γ 1.492 (calc.) (white light); 2V_(meas) = 63.8(6)°; no dispersion or pleochroism; optical orientation: Y = b; Z ^ c ≈ 22° in obtuse β. Six electron-microprobe analyses gave the following empirical formula, based on 20 O apfu: Ba_(0.95)Si_(6.00)O_(20)H_(14.10). Esquireite is monoclinic, space group C2, with cell parameters a 13.601(4), b 4.9222(10), c 15.092(5) A, β 111.578(19)°, V 939.6(4) A^3, and Z = 2. The eight strongest lines in the X-ray powder diffraction patterns are [d_(obs) A(I)(hkl)]: 7.02(38)(002), 5.11(33)(201), 4.649(66)(003,203), 4.191(100)(111), 3.339(65)(402,311,312), 2.967(32)(205,114,311), 2.343(33)(multiple), and 2.261(35)(multiple). The crystal structure (R_1 = 10.8% for 323 reflections with F_o > 4σ F) contains four-tetrahedra-thick [Si_6O_(13)]^(2–) silicate layers with Ba(H_2O)_8^(2+) polyhedra between the layers.

In order to predict and improve the performance of pixelated detectors, it is important to understand the optical properties of the basic unit of the scintillating structure in the detector. To measure one of the essential optical properties, reflectance, we have used a device composed of a laser and photodiode array. We have also developed an analytical model of the optical phenomena based on Snell's law and the Fresnel equations to simply analyze measured results and reflectance parameters at the interface. The computed and experimentally measured results typically have good agreement, validating the analytical model and measurements. The optical parameters are used as inputs to GEANT4 [1]. The simulations are then leveraged to optimize an imager design before a prototype is built. The optical reflectance was measured by using relatively inexpensive samples. A sample has scintillator, glue, and septum (reflector) layers, and each sample has a different scintillator surface (polished/rough) and/or reflector [ESR film/aluminum-sputtered (coated) ESR film] condition. A high-refractive-index hemisphere was attached on the top surface of a sample to increase the maximum incidence angle at the scintillator-glue interface from 27° to 52°. The sample including ESR film demonstrated average reflectance approximately 1.3 times higher than that from the sample with aluminum-sputtered ESR film as a reflector, and the polished surface condition showed higher reflectance than the rough-cut surface condition.

Abstract The ideal formula for members of the cerchiaraite group is Ba4M4(Si4O12)O2(OH)4Cl2[Si2O3(OH)4], where M represents Mn3+, Fe3+ or Al in the octahedral site. A suffix-based naming scheme is used in which the original cerchiaraite is renamed cerchiaraite-(Mn) and two new minerals are named cerchiaraite-(Fe) and cerchiaraite-(Al). The type localities for cerchiaraite-(Fe) are the Cerchiara mine, Liguria, Italy and the Esquire No. 7 and No. 8 claims, Big Creek, Fresno County, California, USA. The type localities for cerchiaraite-(Al) are the Esquire No. 1 claim, Rush Creek, Fresno County, California, USA and the Esquire No. 7 and No. 8 claims noted above. At the Cerchiara mine, cerchiaraite-(Fe) occurs in small fractures and veinlets in a Jurassic ophiolitic sequence. It is of secondary hydrothermal origin and occurs as tan to brown thin prisms and matted fibres. Cerchiaraite(Fe) and cerchiaraite-(Al) from the Esquire No. 1, No. 7 and No. 8 claims occur in parallel-bedded quartz-sanbornite vein assemblages which formed as a result of fluid interaction along the margin of the vein. At the Esquire No. 1, No. 7 and No. 8 claims, both cerchiaraite-(Fe) and cerchiaraite-(Al) occur as subparallel aggregates of blue to bluish green irregular prisms. Both minerals are transparent with a vitreous lustre, Mohs hardness ~4½ , brittle tenacity, irregular fracture and no cleavage. The calculated density of cerchiaraite-(Fe) is 3.710 g cm-3; the measured density of cerchiaraite-(Al) is 3.69(3) g cm-3and the calculated density is 3.643 g cm-3. Cerchiaraite-(Fe) is uniaxial (+), with ω = 1.741(2) and ε = 1.768(2); it is weakly pleochroic and O is colourless and E is yellow. Cerchiaraite-(Al) is uniaxial (-), with ω = 1.695(2) and e = 1.677(2); it is strongly pleochroic and O is colourless and E is blue. Electron-microprobe analyses yielded empirical formulae ranging from (Ba3.82Na0.02Ca0.04)Σ3.88(Fe3+3.42Ti4+0.27Al3+0.25Mn3+0.04Mg0.02)Σ4.00Si5.62O15.47(OH)9.31Cl2.22 (Cerchiara mine) to Ba4.00(Al3+2.40Fe3+1.12Mg0.15Fe2+0.12Mn2+0.06)Σ3.85Si5.78O15.34(OH)8.75Cl2.91 (Esquire No. 1 claim). Cerchiaraite is tetragonal with Z = 2 and crystallizes in space group I4/mmm. The cell parameters for cerchiaraite-(Fe) are a = 14.3554(12), c = 6.0065(5) Å and V = 1237.80(5) Å3; those for cerchiaraite(Al) are a = 14.317(4), c = 6.0037(18) Å and V = 1230.6(6) Å3. In the cerchiaraite-(Fe) structure, SiO4 tetrahedra share corners forming a four-membered Si4O12 ring. The ring is corner-linked to an edgesharing chain of Fe3+ O6 octahedra running parallel to c. A Cl site alternates along c with the Si4 O12 ring. A large channel in the framework contains Ba atoms around its periphery and statistically distributed Si2 O7 silicate dimers and Cl atoms. The strong blue pleochroic colour is attributed to Fe2+ - Fe3+intervalence charge transfer along the octahedral chain.

Detection and interdiction of nuclear materials in all forms of transport is one of the most critical security issues facing the United States and the rest of the civilized world. Naturally emitted gamma rays by these materials, while abundant and detectable when unshielded, are low in energy and readily shielded. X-ray radiography is useful in detecting the possible presence of shielding material. Positive detection of concealed nuclear materials requires methods which unequivocally detect specific attributes of the materials. These methods typically involve active interrogation by penetrating radiation of neutrons, photons or other particles. Fortunately, nuclear materials, probed by various types of radiation, yield very unique and often strong signatures. Paramount among them are the detectable fission signatures, namely prompt neutrons and gamma rays, and delayed neutrons gamma rays. Other useful signatures are the nuclear states excited by neutrons, via inelastic scattering, or photons, via nuclear resonance fluorescence and absorption. The signatures are very different in magnitude, level of specificity, ease of excitation and detection, signal to background ratios, etc. For example, delayed neutrons are very unique to the fission process, but are scarce, have low energy, and hence are easily absorbed. Delayed gamma rays are more abundant but featureless, and have a higher background from natural sources and more importantly, from activation due to the interrogation sources. The prompt fission signatures need to be measured in the presence of the much higher levels of probing radiation. This requires taking special measures to look for the signatures, sometimes leading to a significant sensitivity loss or a complete inability to detect them. Characteristic gamma rays induced in nuclear materials reflecting their nuclear structure, while rather unique, require very high intensity of interrogation radiation and very high resolution in energy and/or time. The trade off of signatures, their means of stimulation, and methods of detection, will be reviewed.