Study on different isolation technology on the performance of blue micro-LEDs array applications.

In this study, a 3 × 3 blue micro-LED array with a pixel size of 10 × 10 µm2 and a pitch of 15 µm was fabricated on an epilayer grown on a sapphire substrate using metalorganic chemical vapor deposition technology. The fabrication process involved photolithography, wet and dry etching, E-beam evaporation, and ion implantation technology. Arsenic multi-energy implantation was utilized to replace the mesa etching for electrical isolation, where the implantation depth increased with the average energy. Different ion depth profiles had varying effects on electrical properties, such as forward current and leakage currents, potentially causing damage to the n-GaN layer and increasing the series resistance of the LEDs. As the implantation depth increased, the light output power and peak external quantum efficiency of the LEDs also increased, improving from 5.33 to 9.82%. However, the efficiency droop also increased from 46.3 to 48.6%.

A Colloidal-Quantum-Dot Integrated U-Shape Micro-Light-Emitting-Diode and Its Photonic Characteristics.

A special micro LED whose light emitting area is laid out in a U-like shape is fabricated and integrated with colloidal quantum dots (CQDs). An inkjet-type machine directly dispenses the CQD layer to the central courtyard-like area of this U-shape micro LED. The blue photons emitted by the U-shape mesa with InGaN/GaN quantum wells can excite the CQDs at the central courtyard area and be converted into green or red ones. The U-shape micro LEDs are coated with Al2O3 by an atomic layer deposition system and exhibit moderate external quantum efficiency (6.51% max.) and high surface recombination because of their long peripheries. Low-temperature measurement also confirms the recovery of the external quantum efficiency due to lower non-radiative recombination from the exposed surfaces. The color conversion efficiency brought by the CQD layer can be as high as 33.90%. A further continuous CQD aging test, which was evaluated by the strength of the CQD emission, under current densities of 100 A/cm2 and 200 A/cm2 injected into the micro LED, showed a lifetime extension of the unprotected CQD emission up to 1321 min in the U-shape device compared to a 39 min lifetime in the traditional case, where the same CQD layer was placed on the top surface of a squared LED.

Real-world osimertinib pretreatment experience in patients with epidermal growth factor receptor T790M mutation-positive locally advanced or metastatic non-small cell lung cancer.

Osimertinib has demonstrated efficacy in patients with epidermal growth factor receptor (EGFR) T790M-positive non-small cell lung cancer (NSCLC) in clinical trials. However, real-world data on its effectiveness remain scarce. Taiwanese patients with T790M-positive locally advanced or metastatic NSCLC and progressive disease following treatment with at least one EGFR tyrosine kinase inhibitor (TKI) were enrolled from the osimertinib early access program. Of the 419 patients (mean age, 63 years; female, 67%), 53% were heavily pretreated (≥ third-line [3L]), making osimertinib a fourth-line (4L) intervention. The median progression-free survival (PFS) was 10.5 months (95% confidence interval [CI]: 8.95-11.41); the 18-month PFS rate was 26.5%. The median overall survival (OS) was 19.0 months (95% CI: 16.30-20.95); the 24-month OS rate was 40.9%. The objective response rate was 32.46%, and the disease control rate was 86.38%. The median time to treatment discontinuation of osimertinib monotherapy was 11.9 months (95% CI: 10.49-13.11). Subgroup analyses of median PFS and OS in the chemotherapy combination group vs. the osimertinib monotherapy group yielded no difference. Central nervous system (CNS) metastasis, number of prior lines of therapy, and types of initial EGFR-TKIs did not significantly impact outcomes. The median PFS values were 9.0 (95% CI: 5.18-11.34) and 10.9 (95% CI: 9.18-11.90) months with and without CNS metastasis, respectively, and 10.8 (95% CI: 8.59-12.69), 13.6 (95% CI: 10.89-16.3), and 9.2 (95% CI: 7.8-10.62) months for second-line (2L), 3L, and ≥4L therapy, respectively. In patients who received osimertinib as 2L therapy, the median PFS values in response to prior afatinib, erlotinib and gefitinib treatment were 11.2 (95% CI: 4.85-4.79), 10.5 (95% CI: 8.59-20.26) and 8.7 (95% CI: 7.21-16.79) months, respectively. Overall, real-world data from Taiwan support the clinical benefits of osimertinib in EGFR T790M -positive NSCLC.

Developing a Cost-Effective Surgical Scheduling System Applying Lean Thinking and Toyota's Methods for Surgery-Related Big Data for Improved Data Use in Hospitals: User-Centered Design Approach.

BACKGROUND: Surgical scheduling is pivotal in managing daily surgical sequences, impacting patient experience and hospital resources significantly. With operating rooms costing approximately US $36 per minute, efficient scheduling is vital. However, global practices in surgical scheduling vary, largely due to challenges in predicting individual surgeon times for diverse patient conditions. Inspired by the Toyota Production System's efficiency in addressing similar logistical challenges, we applied its principles as detailed in the book "Lean Thinking" by Womack and Jones, which identifies processes that do not meet customer needs as wasteful. This insight is critical in health care, where waste can compromise patient safety and medical quality. OBJECTIVE: This study aims to use lean thinking and Toyota methods to develop a more efficient surgical scheduling system that better aligns with user needs without additional financial burdens. METHODS: We implemented the 5 principles of the Toyota system: specifying value, identifying the value stream, enabling flow, establishing pull, and pursuing perfection. Value was defined in terms of meeting the customer's needs, which in this context involved developing a responsive and efficient scheduling system. Our approach included 2 subsystems: one handling presurgery patient data and another for intraoperative and postoperative data. We identified inefficiencies in the presurgery data subsystem and responded by creating a comprehensive value stream map of the surgical process. We developed 2 Excel (Microsoft Corporation) macros using Visual Basic for Applications. The first calculated average surgery times from intra- or postoperative historic data, while the second estimated surgery durations and generated concise, visually engaging scheduling reports from presurgery data. We assessed the effectiveness of the new system by comparing task completion times and user satisfaction between the old and new systems. RESULTS: The implementation of the revised scheduling system significantly reduced the overall scheduling time from 301 seconds to 261 seconds (P=.02), with significant time reductions in the revised process from 99 seconds to 62 seconds (P<.001). Despite these improvements, approximately 21% of nurses preferred the older system for its familiarity. The new system protects patient data privacy and streamlines schedule dissemination through a secure LINE group (LY Corp), ensuring seamless flow. The design of the system allows for real-time updates and has been effectively monitoring surgical durations daily for over 3 years. The "pull" principle was demonstrated when an unplanned software issue prompted immediate, user-led troubleshooting, enhancing system reliability. Continuous improvement efforts are ongoing, except for the preoperative patient confirmation step, which requires further enhancement to ensure optimal patient safety. CONCLUSIONS: Lean principles and Toyota's methods, combined with computer programming, can revitalize surgical scheduling processes. They offer effective solutions for surgical scheduling challenges and enable the creation of a novel surgical scheduling system without incurring additional costs.

Design and simulation of light field patterns for angular color variation reduction in micro-LED and mini-LED RGB arrays.

We propose a methodology to mitigate angular color variation in full-color micron-scale LED arrays. By simulating light field distribution for red (AlGaAs) and green/blue (GaN) light across various RGB micro-LED sizes, we can select matching light field patterns for RGB chips, reducing angular color variation from 0.0201 to 0.0030. Applying this method to full-color mini-LED assemblies achieves a reduction from 0.0128 to 0.0032 by matching light field patterns with varying substrate thicknesses. This straightforward approach aligns with current mass transfer processes, offering practical implementation.

Enhancing photoluminescence performance of perovskite quantum dots with plasmonic nanoparticles: insights into mechanisms and light-emitting applications.

Perovskite quantum dots (QDs) are considered as promising materials for numerous optoelectronic applications due to their narrow emission spectra, high color purity, high photoluminescence quantum yields (PLQYs), and cost-effectiveness. Herein, we synthesized various types of perovskite QDs and incorporated Au nanoparticles (NPs) to systematically investigate the impact of plasmonic effects on the photoluminescence performance of perovskite QDs. The PLQYs of the QDs are enhanced effectively upon the inclusion of Au NPs in the solutions, with an impressive PLQY approaching 99% achieved. The PL measurements reveal that the primary mechanism behind the PL improvement is the accelerated rate of radiative recombination. Furthermore, we integrate perovskite QDs and Au NPs, which function as color conversion layers, with blue light-emitting diodes (LEDs), achieving a remarkable efficiency of 140.6 lm W-1. Additionally, we prepare photopatternable thin films of perovskite QDs using photocrosslinkable polymers as the matrix. Microscale patterning of the thin films is accomplished, indicating that the addition of plasmonic NPs does not adversely affect their photopatternable properties. Overall, our research not only elucidates the underlying mechanisms of plasmonic effects on perovskite QDs but presents a practical method for enhancing their optical performance, paving the way for next-generation optoelectronic applications, including high-definition micro-LED panels.

Clinical implications of PNA­sequencing as a complementary test for EGFR mutation analysis in human lung cancer.

Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) are the first-line regimen for the treatment of non-small cell lung cancer (NSCLC) patients with EGFR mutations. However, false-negative results are occasionally observed, even with FDA-approved molecular tests. Such examples in have been reported in our pilot study showing a slightly upward-shifted amplification curve using commercial reverse transcription-quantitative (RT-q)PCR. Verification using peptide nucleic acid (PNA) clamping-sequencing, which has a sensitivity of ~0.1%, may allow better prediction of which patients will benefit from EGFR-TKI therapy. To confirm this hypothesis, samples were prospectively collected from 1,783 lung cancer cases diagnosed in National Cheng Kung University Hospital between 2012-2018. An independent lung cancer cohort of 1,944 cases was also recruited from other hospitals. The clinical significance of mutant-enriched PCR with PNA-sequencing was analyzed and patient outcomes were followed. A total of 17 of 34 cases (50%) were found to harbor EGFR mutations by PNA-sequencing. A total of 22 cases were discovered in the independent lung cancer cohort, and 14 of these (63.6%) cases had EGFR mutations. TKIs were administered to 14 of the 17 mutation-positive patients, and a partial response was observed in 4 cases and stable disease in 10 cases. Patients with EGFR mutations receiving a TKI regimen had a longer overall survival (OS) (median: 40.0 vs. 10.0 months) compared with those without treatment. The difference in OS was not significant. Based on the results of the present study, combining RT-qPCR with PNA-sequencing may be a practical supplementary technology in a clinical molecular laboratory for a subset of lung cancer patients in selection of EGFR TKI therapy.

Generation and validation of a predictive model for estimating survival among patients with EGFR-mutant non-small cell lung cancer.

Although epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) have become the standard therapy for patients with EGFR-mutant non-small cell lung cancer (NSCLC), treatment outcomes vary significantly. Previous studies have indicated that concurrent mutations may compromise the effectiveness of first-line EGFR-TKIs. However, given the high cost of next-generation sequencing, this information is often inaccessible in routine clinical practice. A prediction model based on pre-treatment clinical characteristics may thus offer a more practical solution. This study established a nomogram based on pretreatment clinical characteristics to stratify patients according to optimal treatment strategies. We retrospectively reviewed 761 patients with EGFR-mutant NSCLC who received first- or second-generation EGFR-TKIs at a tertiary referral center between 2010 and 2019. The pretreatment clinical characteristics and progression-free survival data were collected. Using COX proportional hazard regression analysis, we constructed a nomogram based on seven clinically significant prognostic factors: sex, Eastern Cooperative Oncology Group performance status, histology subtype, mutation subtype, stage, and metastasis to the liver and brain. Our nomogram could stratify patients into three groups with different risks for disease progression and was validated in a patient cohort from other hospitals. This risk stratification can provide additional information for determining the optimal first-line treatment strategy for patients with EGFR-mutant NSCLC.

Distinct Features of Plasma Ultrashort Single-Stranded Cell-Free DNA as Biomarkers for Lung Cancer Detection.

BACKGROUND: Using broad range cell-free DNA sequencing (BRcfDNA-Seq), a nontargeted next-generation sequencing (NGS) methodology, we previously identified a novel class of approximately 50 nt ultrashort single-stranded cell-free DNA (uscfDNA) in plasma that is distinctly different from 167 bp mononucleosomal cell-free DNA (mncfDNA). We hypothesize that uscfDNA possesses characteristics that are useful for disease detection. METHODS: Using BRcfDNA-Seq, we examined both cfDNA populations in the plasma of 18 noncancer controls and 14 patients with late-stage nonsmall cell lung carcinoma (NSCLC). In comparison to mncfDNA, we assessed whether functional element (FE) peaks, fragmentomics, end-motifs, and G-Quadruplex (G-Quad) signatures could be useful features of uscfDNA for NSCLC determination. RESULTS: In noncancer participants, compared to mncfDNA, uscfDNA fragments showed a 45.2-fold increased tendency to form FE peaks (enriched in promoter, intronic, and exonic regions), demonstrated a distinct end-motif-frequency profile, and presented with a 4.9-fold increase in G-Quad signatures. Within NSCLC participants, only the uscfDNA population had discoverable FE peak candidates. Additionally, uscfDNA showcased different end-motif-frequency candidates distinct from mncfDNA. Although both cfDNA populations showed increased fragmentation in NSCLC, the G-Quad signatures were more discriminatory in uscfDNA. Compilation of cfDNA features using principal component analysis revealed that the first 5 principal components of both cfDNA subtypes had a cumulative explained variance of >80%. CONCLUSIONS: These observations indicate that the distinct biological processes of uscfDNA and that FE peaks, fragmentomics, end-motifs, and G-Quad signatures are uscfDNA features with promising biomarker potential. These findings further justify its exploration as a distinct class of biomarker to augment pre-existing liquid biopsy approaches.

Low neutrophil-to-lymphocyte ratio predicts overall survival benefit in advanced NSCLC patients with low PD-L1 expression and receiving chemoimmunotherapy.

Although combination therapy including chemotherapy and immune checkpoint inhibitors (ICIs) improves overall survival (OS) of patients with non-small-cell lung cancer (NSCLC), there is a higher incidence of adverse events and treatment discontinuation. Since programmed death-ligand 1 (PD-L1) could not serve as a predictive biomarker, we investigated the neutrophil-to-lymphocyte ratio (NLR) as a predictive biomarker. In our previous research, we demonstrated that a low NLR could predict survival benefits when patients with high PD-L1 expression (> 50%) received chemoimmunotherapy as opposed to immunotherapy alone. In this current study, our objective is to evaluate this predictive capacity in patients with low PD-L1 expression (< 50%). A total of 142 patients were enrolled, 28 receiving combination therapy and 114 receiving chemotherapy alone. Progression-free survival (PFS) and OS were estimated using the Kaplan-Meier method and compared using the log-rank test. Patients who received combination therapy had significantly better PFS and OS than those who received monotherapy. In the subgroup of patients with low NLR, those who received combination therapy exhibited extended PFS and OS with clinical significance, which was also confirmed by multivariate Cox regression analysis. Our study demonstrates the potential use of NLR as a biomarker for predicting survival benefits when receiving combination therapy with chemotherapy and ICIs in patients with advanced NSCLC and low PD-L1 expression.

Navigating the challenges of invasive pulmonary aspergillosis in lung cancer treatment: a propensity score study.

Background: Invasive pulmonary aspergillosis (IPA) can negatively impact cancer patients' survival. It remains uncertain whether IPA's impact on patient outcomes varies by treatment approach in advanced lung cancer. Objectives: To explore the association between IPA and outcomes in patients with advanced lung cancer receiving different treatments. Design: A retrospective cohort study. Methods: We enrolled patients with advanced-stage lung cancer between 2013 and 2021 at a college hospital in Taiwan and used the 2021 European Organization for Research and Treatment of Cancer/Mycoses Study Group Education and Research Consortium consensus for IPA diagnosis. Multivariable logistic regression was used to identify the IPA risk factors. We compared overall survival (OS) and postgalactomannan (GM) test survival between the IPA and control groups using multivariable Cox proportional hazards regression and the Kaplan-Meier method with propensity score matching (PSM). Results: Among 2543 patients with advanced-stage lung cancer, 290 underwent a GM test, of which 34 (11.7%) were diagnosed with IPA. Patients undergoing chemotherapy (HR = 4.02, p = 0.027) and immunotherapy [hazard ratio (HR) = 3.41, p = 0.076] tended to have IPA. Compared to the control group, the IPA group had shorter median OS (14.4 versus 9.9 months, p = 0.030) and post-GM test survival (4.5 versus 1.9 months, p = 0.003). IPA was associated with shorter OS (log-rank p = 0.014 and 0.018 before and after PSM, respectively) and shorter 1-year and 2-year survival post-GM test (HR = 1.65 and 1.66, respectively). Patients receiving chemotherapy or immunotherapy had a shorter post-GM test survival if they had IPA. Conclusions: IPA tended to be diagnosed more frequently in patients receiving chemotherapy or immune checkpoint inhibitors. Patients diagnosed with IPA are associated with shorter survival. Larger cohort studies are needed to verify the observations.

T790M detection rate after first-line combination therapy with bevacizumab and EGFR-TKIs in advanced NSCLC (TERRA Study).

Real-world data regarding the T790M mutation rate after acquiring resistance to first-line combination therapy with epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) and bevacizumab in patients with advanced non-small-cell lung cancer (NSCLC) are limited. The present study was aimed at analyzing predictors of acquired T790M mutations in this patient group. A total of 107 patients who received first-line combination therapy with EGFR-TKIs and bevacizumab at 11 tertiary referral centers in Taiwan were enrolled in this multicenter retrospective study. Survival data and genomic test results after acquiring resistance were analyzed. We discovered that patients who received a combination of afatinib, a second generation EGFR-TKI, and bevacizumab showed better progression-free survival (PFS). After disease progression, 59 patients (55.1%) were confirmed to test positive for EGFR T790M. A longer duration of first-line therapy could be a predictor of subsequent T790M mutations. To our knowledge, this is one of the few and early studies to demonstrate the T790M mutation rate after first-line combination therapy with an EGFR-TKI and bevacizumab. Whether the longer PFS afforded by the addition of bevacizumab could lead to subsequent T790M mutations needs further investigation.

Ameliorating Uniformity and Color Conversion Efficiency in Quantum Dot-Based Micro-LED Displays through Blue-UV Hybrid Structures.

Quantum dot (QD)-based RGB micro light-emitting diode (µ-LED) technology shows immense potential for achieving full-color displays. In this study, we propose a novel structural design that combines blue and quantum well (QW)-intermixing ultraviolet (UV)-hybrid µ-LEDs to achieve high color-conversion efficiency (CCE). For the first time, the impact of various combinations of QD and TiO2 concentrations, as well as thickness variations on photoluminescence efficiency (PLQY), has been systematically examined through simulation. High-efficiency color-conversion layer (CCL) have been successfully fabricated as a result of these simulations, leading to significant savings in time and material costs. By incorporating scattering particles of TiO2 in the CCL, we successfully scatter light and disperse QDs, effectively reducing self-aggregation and greatly improving illumination uniformity. Additionally, this design significantly enhances light absorption within the QD films. To enhance device reliability, we introduce a passivation protection layer using low-temperature atomic layer deposition (ALD) technology on the CCL surface. Moreover, we achieve impressive CCE values of 96.25% and 92.91% for the red and green CCLs, respectively, by integrating a modified distributed Bragg reflector (DBR) to suppress light leakage. Our hybrid structure design, in combination with an optical simulation system, not only facilitates rapid acquisition of optimal parameters for highly uniform and efficient color conversion in µ-LED displays but also expands the color gamut to achieve 128.2% in the National Television Standards Committee (NTSC) space and 95.8% in the Rec. 2020 standard. In essence, this research outlines a promising avenue towards the development of bespoke, high-performance µ-LED displays.

Investigations on the high performance of InGaN red micro-LEDs with single quantum well for visible light communication applications.

In this study, we have demonstrated the potential of InGaN-based red micro-LEDs with single quantum well (SQW) structure for visible light communication applications. Our findings indicate the SQW sample has a better crystal quality, with high-purity emission, a narrower full width at half maximum, and higher internal quantum efficiency, compared to InGaN red micro-LED with a double quantum wells (DQWs) structure. The InGaN red micro-LED with SQW structure exhibits a higher maximum external quantum efficiency of 5.95% and experiences less blueshift as the current density increases when compared to the DQWs device. Furthermore, the SQW device has a superior modulation bandwidth of 424 MHz with a data transmission rate of 800 Mbit/s at an injection current density of 2000 A/cm2. These results demonstrate that InGaN-based SQW red micro-LEDs hold great promise for realizing full-color micro-display and visible light communication applications.

Chemotherapy outcomes in EGFR-TKI resistant patients with common and uncommon EGFR mutation: An exploratory retrospective cohort study.

BACKGROUND: Some prospective studies have shown that second-generation tyrosine kinase inhibitors (TKIs) provide better control in patients with non-small cell lung cancer (NSCLC) with uncommon epidermal growth factor receptor (EGFR) mutations. However, studies comparing second-line chemotherapy efficacy between NSCLC patients with common and uncommon EGFR mutations remain rare. This retrospective study compared treatment outcomes in these patients. METHODS: Patients with EGFR-mutated advanced-stage NSCLC who received first-line EGFR-TKIs in a tertiary referral center were retrospectively reviewed between January 2010 and August 2022. Patients with a negative T790M test at disease progression who received second-line chemotherapy were enrolled. We compared progression-free (PFS) and overall (OS) survival between advanced NSCLC patients with common and uncommon EGFR mutations using Kaplan-Meier and log-rank tests. RESULTS: In total, 209 (54.8%) patients had a negative T790M mutation test and received second-line chemotherapy, of which 192 (91.8%) had a common EGFR mutation (exon 19 deletion or exon 21 L858R substitution), and 17 (8.2%) had an uncommon EGFR mutation. Patients with common EGFR mutations had significantly longer PFS than those with uncommon EGFR mutations (4.57 vs. 2.57 months, p = 0.031). A Cox proportional hazard regression analysis controlling for potential confounding factors indicated that an uncommon EGFR mutation was an independent prognostic factor for PFS. CONCLUSION: This study suggests that patients with uncommon EGFR mutations have poorer chemotherapy responses and shorter survival than those with common EGFR mutations. The development of new treatment strategies for these patients remains an unmet need.

Cigarette smoke increases susceptibility of alveolar macrophages to SARS-CoV-2 infection through inducing reactive oxygen species-upregulated angiotensin-converting enzyme 2 expression.

Alveolar macrophages (AMs) are the drivers of pulmonary cytokine storm in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. This study aimed to investigate clinical-regulatory factors for the entrance protein of SARS-CoV-2, angiotensin-converting enzyme 2 (ACE2) in AMs. Human AMs were collected from 56 patients using bronchoalveolar lavage. ACE2 expression in AMs was positively correlated with smoking pack-year (Spearman's r = 0.347, P = 0.038). In multivariate analysis, current smoking was associated with increased ACE2 in AMs (ß-coefficient: 0.791, 95% CI 0.019-1.562, P = 0.045). In vitro study, ex-vivo human AMs with higher ACE2 were more susceptible to SARS-CoV-2 pseudovirus (CoV-2 PsV). Treating human AMs using cigarette smoking extract (CSE) increases the ACE2 and susceptibility to CoV-2 PsV. CSE did not significantly increase the ACE2 in AMs of reactive oxygen species (ROS) deficient Cybb-/- mice; however, exogenous ROS increased the ACE2 in Cybb-/- AMs. N-acetylcysteine (NAC) decreases ACE2 by suppressing intracellular ROS in human AMs. In conclusion, cigarette smoking increases the susceptibility to SARS-CoV-2 by increasing ROS-induced ACE2 expression of AMs. Further investigation into the preventive effect of NAC on the pulmonary complications of COVID-19 is required.

Effect of radiative and nonradiative energy transfer processes of light-emitting diodes combined with quantum dots for visible light communication.

Though light-emitting diodes (LEDs) combined with various color conversion techniques have been widely explored for VLC (visible light communication), E-O (electro-optical) frequency responses of devices with quantum dots (QDs) embedded within the nanoholes have rarely been addressed. Here we propose LEDs with embedded photonic crystal (PhC) nanohole patterns and green light QDs for studying small-signal E-O frequency bandwidths and large signal on-off keying E-O responses. We observe that the E-O modulation quality of PhC LEDs with QDs is better than a conventional LED with QDs when the overall blue mixed with green light output signal is considered. However, the optical response of only QD converted green light shows a contradictory result. The slower E-O conversion response is attributed to multi-path green light generation from both radiative and nonradiative energy transfer processes for QDs coated on the PhC LEDs.

The Size-Dependent Photonic Characteristics of Colloidal-Quantum-Dot-Enhanced Micro-LEDs.

Colloidal CdSe/ZnS quantum dots (QD) enhanced micro-LEDs with sizes varying from 10 to 100 µm were fabricated and measured. The direct photolithography of quantum-dot-contained photoresists can place this color conversion layer on the top of an InGaN-based micro-LED and have a high throughput and semiconductor-grade precision. Both the uncoated and coated devices were characterized, and we determined that much higher brightness of a QD-enhanced micro-LED under the same current level was observed when compared to its AlGaInP counterpart. The color stability across the device sizes and injection currents were also examined. QD LEDs show low redshift of emission wavelength, which was recorded within 1 nm in some devices, with increasing current density from 1 to 300 A/cm2. On the other hand, the light conversion efficiency (LCE) of QD-enhanced micro-LEDs was detected to decrease under the high current density or when the device is small. The angular intensities of QD-enhanced micro-LEDs were measured and compared with blue devices. With the help of the black matrix and omnidirectional light emission of colloidal QD, we observed that the angular intensities of the red and blue colors are close to Lambertian distribution, which can lead to a low color shift in all angles. From our study, the QD-enhanced micro-LEDs can effectively increase the brightness, the color stability, and the angular color match, and thus play a promising role in future micro-display technology.

Effect of BIM expression on the prognostic value of PD-L1 in advanced non-small cell lung cancer patients treated with EGFR-TKIs.

The role of Programmed Cell Death Ligand 1 (PD-L1) expression in predicting epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKIs) efficacy remains controversial. Recent studies have highlighted that tumor-intrinsic PD-L1 signaling can be modulated by STAT3, AKT, MET oncogenic pathway, epithelial-mesenchymal transition, or BIM expression. This study aimed to investigate whether these underlying mechanisms affect the prognostic role of PD-L1. We retrospectively enrolled patients with EGFR mutant advanced stage NSCLC who received first-line EGFR-TKI between January 2017 and June 2019, the treatment efficacy of EGFR-TKI was assessed. Kaplan-Meier analysis of progression-free survival (PFS) revealed that patients with high BIM expression had shorter PFS, regardless of PD-L1 expression. This result was also supported by the COX proportional hazard regression analysis. In vitro, we further proved that the knockdown of BIM, instead of PDL1, induced more cell apoptosis following gefitinib treatment. Our data suggest that among the pathways affecting tumor-intrinsic PD-L1 signaling, BIM is potentially the underlying mechanism that affects the role of PD-L1 expression in predicting response to EGFR TKI and mediates cell apoptosis under treatment with gefitinib in EGFR-mutant NSCLC. Further prospective studies are required to validate these results.

Modified Distributed Bragg Reflectors for Color Stability in InGaN Red Micro-LEDs.

The monolithic integration of InGaN-based micro-LEDs is being of interest toward developing full-color micro-displays. However, the color stability in InGaN red micro-LED is an issue that needs to be addressed. In this study, the modified distributed Bragg reflectors (DBRs) were designed to reduce the transmission of undesired spectra. The calculated optical properties of the InGaN red micro-LEDs with conventional and modified DBRs have been analyzed, respectively. The CIE 1931 color space and the encoded 8-bit RGB values are exhibited for the quantitative assessment of color stability. The results suggest the modified DBRs can effectively reduce the color shift, paving the way for developing full-color InGaN-based micro-LED displays.