High dynamic range display systems

High contrast ratio (CR) enables a display system to faithfully reproduce the real objects. However, achieving high contrast, especially high ambient contrast (ACR), is a challenging task. In this dissertation, two display systems with high CR are discussed: high ACR augmented reality (AR) display and high dynamic range (HDR) display. For an AR display, we improved its ACR by incorporating a tunable transmittance liquid crystal (LC) film. The film has high tunable transmittance range, fast response time, and is fail-safe. To reduce the weight and size of a display system, we proposed a functional reflective polarizer, which can also help people with color vision deficiency. As for the HDR display, we improved all three aspects of the hardware requirements: contrast ratio, color gamut and bit-depth. By stacking two liquid crystal display (LCD) panels together, we have achieved CR over one million to one, 14-bit depth with 5V operation voltage, and pixel-by-pixel local dimming. To widen color gamut, both photoluminescent and electroluminescent quantum dots (QDs) have been investigated. Our analysis shows that with QD approach, it is possible to achieve over 90% of the Rec. 2020 color gamut for a HDR display. Another goal of an HDR display is to achieve the 12-bit perceptual quantizer (PQ) curve covering from 0 to 10,000 nits. Our experimental results indicate that this is difficult with a single LCD panel because of the sluggish response time. To overcome this challenge, we proposed a method to drive the light emitting diode (LED) backlight and the LCD panel simultaneously. Besides relatively fast response time, this approach can also mitigate the imaging noise. Finally yet importantly, we improved the display pipeline by using a HDR gamut mapping approach to display HDR contents adaptively based on display specifications. A psychophysical experiment was conducted to determine the display requirements

Light extraction analysis and enhancement in a quantum dot light emitting diode

We apply a rigorous dipole model to analyze the light outcoupling and angular performance of quantum dot light emitting diode (QLED). To illustrate the design principles, we use a red QLED as an example and compare its performance with an organic light emitting diode (OLED). By combining a high refractive index glass substrate with macroextractors, our simulation results indicate that the light outcoupling efficiency is doubled from similar to 40% to similar to 80%. After analyzing the light emission spectra and angular radiation pattern of the device, we confirm that QLED has a much weaker color shift than OLED

Tuning the correlated color temperature of white LED with a guest-host liquid crystal

We demonstrate an electro-optic method to tune the correlated color temperature (CCT) of white light-emitting-diode (WLED) with a color conversion film, consisting of fluorescent dichroic dye doped in a liquid crystal host. By controlling the molecular reorientation of dichroic dyes, the power ratio of the transmitted blue and red lights of the white light can be accurately manipulated, resulting in different CCT. In a proof-of-concept experiment, we showed that the CCT of a yellow phosphor-converted WLED can be tuned from 3200 K to 4100 K. With further optimizations, the tuning range could be enlarged to 2500 K with fairly good color performance: luminous efficacy of radiation (LER) \u3e 300 lm/W, color rendering index (CRI) \u3e 75, and Duv \u3c 0.005. Besides, the operation voltage is lower than 5 V and good angular color uniformity is achieved with remote-phosphor coating. This approach is promising for next generation smart lighting

Effect of salt stress on growth and physiological parameters of sorghum genotypes at an early growth stage

404-411Physiological regulation affects plant salinity tolerance. The objective of this research was to investigate the effect of salt stress on the physiological regulation in sorghum at early growth stage. Two sorghum genotypes (GT), Bayeqi (salt-tolerant) and PL212 (salt-sensitive), were grown in an artificial climate chamber with a nutrition solution containing 0，80, 160, and 240 mM NaCl. Results showed that salt-tolerant sorghum had enhanced activities of antioxidant enzymes including catalase (CAT), peroxidase (POD), and superoxide dismutase (SOD), and increased stress-related osmolytes including free amino acids, and reducing and soluble sugars. Furthermore, ion regulation plays an important role in the osmotic adjustment. Results also suggest that K+/Na+ and Ca2+/Na+ ratios are associated with tolerance under salt-stressed environments and higher Na+ and lower K+ and Ca2+ concentrations are deleterious to sorghum growth. As a result, under salt-stressed environments, the salt-tolerant sorghum GT had better growth performance than salt-sensitive sorghum GT, which was evidenced by a greater plant high, leaf area, leaf fresh weight, and root fresh weight. Overall, under salt-stressed environments, the salt-tolerant sorghum GT had better growth performance including yield than salt-sensitive sorghum GT, which was evidenced by a greater plant high, leaf area, leaf fresh weight, and root fresh weight

Optical rotatory power of polymer-stabilized blue phase liquid crystals

Macroscopically, a polymer-stabilized blue phase liquid crystal (BPLC) is assumed to be an optically isotropic medium. Our experiment challenges this assumption. Our results indicate that the optical rotatory power (ORP) of some nano-scale double-twist cylinders in a BPLC composite causes the polarization axis of the transmitted light to rotate a small angle, which in turn leaks through the crossed polarizers. Rotating the analyzer in azimuthal direction to correct this ORP can greatly improve the contrast ratio. A modified De Vries equation based on a thin twisted-nematic layer is proposed to explain the observed phenomena

Enhancing the outcoupling efficiency of quantum dot LEDs with internal nano-scattering pattern

We report an effective method to extract light from quantum-dot light emitting diodes (QLEDs) by embedding an internal nano-scattering pattern structure. We use finite-difference time-domain method to analyze the light extraction efficiency of red QLEDs with periodic, quasi-random, and random internal nano-scattering pattern structures. Our simulation results indicate that random internal nano-scattering pattern can greatly enhance the outcoupling efficiency while keeping wide viewing angle for the red QLED. Similar results are obtained by extending this approach to green and blue QLEDs. With the proposed red, green, and blue QLEDs combination, we achieve 105.1% Rec. 2020 color gamut in CIE 1976 color space. We demonstrate that internal nano-scattering pattern structures are attractive for display applications, especially for enhancing the outcoupling efficiency of blue QLEDs

Identification and validation of PCSK9 as a prognostic and immune-related influencing factor in tumorigenesis: a pan-cancer analysis

IntroductionProprotein convertase subtilisin/kexin-9 (PCSK9) has been primarily studied in the cardiovascular field however, its role in cancer pathophysiology remains incompletely defined. Recently, a pivotal role for PCSK9 in cancer immunotherapy was proposed based on the finding that PCSK9 inhibition was associated with enhancing the antigen presentation efficacy of target programmed cell death-1 (PD-1). Herein, we provide results of a comprehensive pan-cancer analysis of PCSK9 that assessed its prognostic and immunological functions in cancer.MethodsUsing a variety of available online cancer-related databases including TIMER, cBioPortal, and GEPIA, we identified the abnormal expression of PCSK9 and its potential clinical associations in diverse cancer types including liver, brain and lung. We also validated its role in progression-free survival (PFS) and immune infiltration in neuroblastoma.ResultsOverall, the pan-cancer survival analysis revealed an association between dysregulated PCSK9 and poor clinical outcomes in various cancer types. Specifically, PCSK9 was extensively genetically altered across most cancer types and was consistently found in different tumor types and substages when compared with adjacent normal tissues. Thus, aberrant DNA methylation may be responsible for PCSK9 expression in many cancer types. Focusing on liver hepatocellular carcinoma (LIHC), we found that PCSK9 expression correlated with clinicopathological characteristics following stratified prognostic analyses. PCSK9 expression was significantly associated with immune infiltrate since specific markers of CD8+ T cells, macrophage polarization, and exhausted T cells exhibited different PCSK9-related immune infiltration patterns in LIHC and lung squamous cell carcinoma. In addition, PCSK9 was connected with resistance of drugs such as erlotinib and docetaxel. Finally, we validated PCSK9 expression in clinical neuroblastoma samples and concluded that PCSK9 appeared to correlate with a poor PFS and natural killer cell infiltration in neuroblastoma patients.ConclusionPCSK9 could serve as a robust prognostic pan-cancer biomarker given its correlation with immune infiltrates in different cancer types, thus potentially highlighting a new direction for targeted clinical therapy of cancers

Effect of salt stress on growth and physiological parameters of sorghum genotypes at an early growth stage

Physiological regulation affects plant salinity tolerance. The objective of this research was to investigate the effect of salt stress on the physiological regulation in sorghum at early growth stage. Two sorghum genotypes (GT), Bayeqi (salt-tolerant) and PL212 (salt-sensitive), were grown in an artificial climate chamber with a nutrition solution containing 0，80, 160, and 240 mM NaCl. Results showed that salt-tolerant sorghumhad enhanced activities of antioxidant enzymes including catalase (CAT), peroxidase (POD), and superoxide dismutase (SOD), and increased stress-related osmolytes including free amino acids, and reducing and soluble sugars. Furthermore, ion regulation plays an important role in the osmotic adjustment. Results also suggest that K+/Na+ and Ca2+/Na+ ratios are associated with tolerance under salt-stressed environments and higher Na+ and lower K+ and Ca2+ concentrations are deleterious to sorghum growth. As a result, under salt-stressed environments, the salt-tolerant sorghum GT had better growth performance than salt-sensitive sorghumGT, which was evidenced by a greater plant high, leaf area, leaf fresh weight, and root fresh weight. Overall, under salt-stressed environments, the salt-tolerant sorghum GT had better growth performance including yield than salt-sensitive sorghum GT, which was evidenced by a greater plant high, leaf area, leaf fresh weight, and root fresh weigh

Yap1 Hydroxylation Suppress Prostate Cancer Metastasis

View full abstracthttps://openworks.mdanderson.org/leading-edge/1031/thumbnail.jp

Bulletin

https://openspace.dmacc.edu/bulletin/1104/thumbnail.jp