Performance comparison of flip-chip blue-light microLEDs with various passivation.

In this study, arrays of µLEDs in four different sizes (5 × 5 µm2, 10 × 10 µm2, 25 × 25 µm2, 50 × 50 µm2) were fabricated using a flip-chip bonding process. Two passivation processes were investigated with one involving a single layer of SiO2 deposited using plasma-enhanced chemical vapor deposition (PECVD) and the other incorporating Al2O3 deposited by atomic layer deposition (ALD) beneath the SiO2 layer. Owing to superior coverage and protection, the double-layers passivation process resulted in a three-order lower leakage current of µLEDs in the 5 µm chip-sized µLED arrays. Furthermore, higher light output power of µLEDs was observed in each chip-sized µLED array with double layers passivation. Particularly, the highest EQE value 21.9% of µLEDs array with 5 µm × 5 µm chip size was achieved with the double-layers passivation. The EQE value of µLEDs array was improved by 4.4 times by introducing the double-layers passivation as compared with that of µLEDs array with single layer passivation. Finally, more uniform light emission patterns were observed in the µLEDs with 5 µm × 5 µm chip size fabricated by double-layer passivation process using ImageJ software.

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%.

Electrically tunable gradient-index lenses via liquid crystals: beyond the power law.

In this study we present an investigation of electrically tunable progressive lenses utilizing liquid crystals (LC). We introduce a polarized progressive LC lens capable of dynamically adjusting its focal length, functioning as either a positive or negative lens. Our findings reveal that the spatial distribution of lens power within the progressive LC lens, ranging from +4D to -3D, far surpassing the range of -0.87D to +0.87D which one may expect within the parabolic wavefront approximation. For a lens with a 30 mm aperture a total tunable range is 7.6 D (from +5.6D to -2D) which is 4.75 times larger than the traditional parabolic prediction∼1.6D (from +0.8D to -0.8D). This study not only challenges conventional limitations set by optical phase differences in gradient-index LC lenses (the power law) but also ushers in a new possibility for ophthalmic applications. The profound insights and outcomes presented in this paper redefine the landscape of LC lenses, paving the way for transformative advancements in optics and beyond.

Current Confinement Effect on the Performance of Blue Light Micro-LEDs with 10 µm Dimension.

The current confinement effect on the micro-LED (µLED) with a 10 µm dimension was simulated using SpeCLED software. In this study, three p-contact sizes were considered: 2 µm × 2 µm, 5 µm × 5 µm, and 8 µm × 8 µm dimensions for µLEDs with a 10 µm dimension. According to the simulation data, the highest external quantum efficiency (EQE) of 13.24% was obtained with a 5 µm × 5 µm contact size. The simulation data also showed that the µLEDs with narrow contact sizes experienced higher operating temperatures due to the current crowding effect. The experimental data revealed a red-shift effect in narrow contact sizes, indicating higher heat generation in those devices. As the contact sizes increased from 2 to 8 µm, the turn-on voltage decreased due to lower equivalent resistance. Additionally, the leakage current increased from 44 pA to 1.6 nA at a reverse voltage of -5 V. The study found that the best performance was achieved with a contact ratio of 0.5, which resulted in the highest EQE at 9.95%. This superior performance can be attributed to the better current confinement of the µLED compared to the µLED with a contact ratio of 0.8, resulting in lower leakage current and improved current spreading when compared to the µLED with a contact ratio of 0.2.

Retrospective Study on the Impact of COVID-19 Lockdown on Patients with Type 2 Diabetes in Northern Taiwan.

Background: During the COVID-19 pandemic, the national lockdown had a significant impact on healthcare systems and diabetes management. The results of relevant studies were inconsistent. The aim of the study was to investigate the impact of lockdown on glycemic control among patients with type 2 diabetes mellitus(T2D) in Taiwan. Methods: This was a retrospective study conducted in a single regional hospital in Northern Taiwan. The clinic characteristics of the patients were summarized. Anthropometric and biochemical data before and after the lockdown were collected and analyzed. Stepwise multiple regression analysis was performed to identify the independent determinants of variables, including baseline characteristics and laboratory parameters, for the changes in glycated hemoglobin(HbA1c). Results: A total of 943 (females 48.5%) patients with T2D were enrolled. The mean age of the patients was 60.6±12.3years, with a mean HbA1c of 7.0±1.0%, a mean diabetes duration of 7.3±4.6years, and a mean body mass index(BMI) of 26.5±4.5kg/m2. The overall means of HbA1c and fasting blood glucose were significantly improved after the lockdown compared to before (7.0±1.0 vs 6.8±0.9, p<0.001 and 132.2±33.3 vs 124.4±30.0, p<0.001, respectively). The proportion of patients achieving HbA1c target (≤7%) was higher after the lockdown compared to before (61.5% vs 68.9%, p<0.001). Stepwise multiple regression analysis revealed that baseline HbA1c before the lockdown was a positive contributor to the change in HbA1c after the lockdown, whereas BMI and co-morbidity with dyslipidemia were negative contributors (standardized coefficient +0.16, p<0.001; -0.07, p=0.025; -0.12, p=0.001, respectively). Conclusion: Our study highlights the benefits of lockdown measures on diabetic control in Northern Taiwan as a single-center experience with the improvement of HbA1c and fasting blood glucose. Understanding these consequences of national lockdown can help healthcare providers to improve diabetes care during the pandemic.

Improved electrical properties of micro light-emitting diode displays by ion implantation technology.

Generally, the inductively coupled plasma-reactive ion etching (ICP-RIE) mesa technology was used to remove p-GaN/MQWs and expose n-GaN for electrical contact in a fabricated micro light-emitting diode (µLED). In this process, the exposed sidewalls were significantly damaged which result in small-sized µLED presenting a strong size-dependent influence. Lower emission intensity was observed in the µLED chip, which can be attributed to the effect of sidewall defect during etch processing. To reduce the non-radiative recombination, the ion implantation using an As+ source to substitute the ICP-RIE mesa process was introduced in this study. The ion implantation technology was used to isolate each chip to achieve the mesa process in the µLED fabrication. Finally, the As+ implant energy was optimized at 40 keV, which exhibited excellent current-voltage characteristics, including low forward voltage (3.2 V @1 mA) and low leakage current (10-9 A@- 5 V) of InGaN blue µLEDs. The gradual multi-energy implantation process from 10 to 40 keV can further improve the electrical properties (3.1 V @1 mA) of µLEDs, and the leakage current was also maintained at 10-9 A@- 5 V.

Intraoperative OK-432 pleurodesis for preventing recurrence of primary spontaneous pneumothorax in children and adolescents: a single-center experience.

BACKGROUND: Primary spontaneous pneumothorax (PSP) commonly occurs in lean, tall, male children and adolescents. To reduce recurrence rates of PSP, chemical pleurodesis could be helpful for patients undergoing video-assisted thoracoscopic surgery (VATS) wedge bullectomy. The efficacy and safety of intraoperative OK-432 (Picibanil) pleurodesis on preventing the recurrence of PSP in pediatric patients remain unclear. METHODS: It is a retrospective observational study in a single center, between 2014 and 2020, enrolled 48 (8 females) pediatric PSP patients with persistent air leakage at the mean age of 16.3 ± 1.1 years to receive VATS wedge bullectomy and pleural abrasion. Twenty patients received additional intraoperative OK-432 pleurodesis. The clinical characteristics of patients, surgical outcomes, and recurrence rates were analyzed. RESULTS: The OK-432 group had longer operation time (118.6 ± 35.6 vs. 96.5 ± 23.3 min; p < 0.05) and higher proportion of postoperative fever (75.0% vs. 28.5%; p = 0.015) than the standard group. No serious adverse events were noted and other surgical outcomes in the two groups were comparable. After a mean follow-up period of 18.1 ± 19.1 months, the OK-432 group had a lower recurrence rate compared with the standard group (5% vs. 28.6%; p < 0.05, odds ratio 0.13, 95% confidence interval: 0.01-1.15), but it had no significant difference in statistics on the Kaplan-Meier curves (log-rank p = 0.105). CONCLUSION: It was the first study that focused on the addition of intraoperative OK-432 pleurodesis for PSP with persistent air leakage in children and adolescents receiving VATS. It demonstrated the efficacy with a low recurrence rate and short-term safety as a single-center experience. LEVEL OF EVIDENCE: Retrospective review, therapeutic study, Level III.

Generation of vector vortex beams by axially symmetric sheared polymer network liquid crystals.

Liquid crystals have been widely used in optoelectronic devices because of their fast response and excellent electro-optic properties. Featuring a unique ability to manipulate light, they are also proposed as a good candidate in topological photonics for further applications. In this study, an axially symmetric sheared polymer network liquid crystal (ASPNLC) is fabricated to demonstrate vector vortex beams. Linearly and circularly polarized light is used to illuminate the sample, and the output vector vortex beams generated from the ASPNLC indicate that the polarization states of the output beams are dependent on the polarization of the incident light. The measured phenomena are modeled on the bases of phase retardation and Jones calculus to eventually calculate the polarization-resolved intensity profiles accordingly. Hence, our experimental study provides a holistic understanding of the method for generating vector vortex beams by an ASPNLC, which is expected to enhance the knowledge of optical mechanisms for liquid crystal applications.

Effects of ITO Contact Sizes on Performance of Blue Light MicroLEDs.

In this study, the effect of ITO contact ratio for blue light micro-light-emitting diode (µLED) with dimensions 40 µm × 40 µm was assessed. The contact ratio from 0.2 to 0.8 was designed for the ratio of electrode area to light-emitting area. As the contact ratio increased from 0.2 to 0.8, the turn-on voltage of µLED decreased. It could be due to the short lateral diffusion length in multiple quantum wells (MQW) and lower parallel resistance for the µLED with a large contact ratio. The leakage currents of single µLED were below 5.1 × 10-9 A, no matter the contact ratio. It means that the contact ratio does not affect the leakage current as measured on single chip. Moreover, µLED array with a 0.8 contact ratio presented the highest output power than other samples (5.25 mW as the current density of 1875 A/cm2). It could attribute to the MQWs usage, the metal contact reflective behavior and less current crowding, which generated more carriers and extracted more lighting from the µLED. The simulation data using SpeCLED software agreed well with these experiments, and µLED with a 0.8 contact ratio showed the best optoelectronic properties.

Study on the performance of high-voltage deep ultraviolet light-emitting diodes.

This study fabricated high-voltage, low-current DUV-LEDs by connecting two devices. Due to better current spreading and the enhanced reflective mirror effect, high-voltage devices present a higher dynamic resistance, emission output power, wall-plug efficiency, external quantum efficiency, and view angle than single traditional devices. The study found that when the injection current was 320 mA, the maximum output power was exhibited at 47.1 mW in the HV sample. The maximum WPE and EQE of high-voltage DUV-LEDs were 2.46% and 5.48%, respectively. Noteworthily, the redshift wavelength shifted from 287.5 to 280.5 nm, less than the traditional device-from 278 to 282 nm. Further, due to the uniform emission patterns in high-voltage devices, the view angle presents 130 degrees at 100 mA input current. In this study, the high-voltage device showed more excellent properties than the traditional device. In particular, it presented a high potential application in high-voltage circuits, which can remove transformers to eliminate extra power consumption.

Image-based polarization detection and material recognition.

We demonstrate a single-shot and image-based polarization detection system for material recognition. The Stokes parameters are measured under a single-shot measurement using 4 electrically tunable liquid crystal wave plates, 4 polarizers, and 4 camera modules. The optical principle is introduced and the experiments are performed. We also use a metallic plate and a glass substrate to demonstrate the material recognition. The impact of this study is to provide a practical way in image-based polarization detection in Advanced Driver Assistance Systems for material recognition which could help in driving safety.

Liquid crystal lens set in augmented reality systems and virtual reality systems for rapidly varifocal images and vision correction: erratum.

We have an addendum for our previous paper [Opt. Express30, 22768 (2022)10.1364/OE.461378] cite previous prior works from the N. A. Riza lab that earlier reported a high speed lens based on digital polarization switching in cascade with birefringent fixed and tunable optical beamforming elements and its application for volumetric displays.

Liquid crystal lens set in augmented reality systems and virtual reality systems for rapidly varifocal images and vision correction.

The major challenges of augmented reality (AR) systems and virtual reality (VR) systems are varifocal images for vergence-accommodation conflict (VAC) and vision corrections. In this paper, we design a liquid crystal (LC) lens set consisting of three LC lenses for varifocal images and vision corrections in AR and VR. Four operating modes of such a LC lens set present three electrically tunable lens powers: 0, -0.79 diopters, -2 diopters, and -3.06 diopters by means of manipulation of polarization of incident light using electrically tunable half-wave-plates. The response time is fast(< 50 ms). We also demonstrate AR and VR systems by adopting the LC lens set to exhibit functions of varifocal images and vision corrections which enable to solve VAC as well as vision problem in AR and VR.

Moyamoya disease with Sjogren disease and autoimmune thyroiditis presenting with left intracranial hemorrhage after messenger RNA-1273 vaccination: A case report.

RATIONALE: The new vaccines are emergently authorized and currently approved for use to protect against the coronavirus disease 2019 (COVID-19) pandemic and serious adverse events are uncommon. Moyamoya disease (MMD) with autoimmune disease is a rare entity and usually presents with intracranial hemorrhage in adults. PATIENT CONCERNS: We reported a 40-year-old female patient with Sjogren disease and autoimmune thyroiditis, who had received the second dose of Moderna (mRNA-1273) vaccination. Three days later, she presented with left intraventricular and intracerebral hemorrhage as a complication. DIAGNOSIS: After a series of diagnostic workups, left intracranial hemorrhage was associated with MMD. INTERVENTIONS: Emergent external ventricular drainage and subsequent stereotactic evacuation of hematoma with insertion of intracranial pressure monitoring were performed. OUTCOMES: Under the care of the neurocritical care team, her physical condition improved gradually. The neurological sequelae was noted by defects of cognitive function, apraxia, agnosia, and impaired executive function. She was discharged after eight weeks with a follow-up in the vascular neurology clinic planning for performing revascularization. LESSONS: To the best of our knowledge, no similar case has been reported before, and this is the first case of MMD complicated with intracerebral and intraventricular hemorrhage after mRNA-1273 vaccination. It is noticeable to assess the vaccine safety surveillance and raise the alertness about moyamoya in patients with autoimmune diseases during the COVID-19 pandemic. Further studies for risk evaluation of COVID-19 vaccines in patients with autoimmune diseases might be required in the future.

Neuroendocrine Carcinoma of the Endometrium with Ectopic Secretion of Parathyroid Hormone Presenting as Hypercalcemia- Related Posterior Reversible Encephalopathy syndrome: A Case Report.

PURPOSE: Posterior reversible encephalopathy syndrome (PRES) displayed various acute neurological symptoms. PRES is a rare presentation of hypercalcemia. Here we present a case with ectopic secretion of parathyroid hormone from neuroendocrine carcinoma of the endometrium presenting as hypercalcemia-related PRES. CASE REPORT: A 67-year-old woman presented with acute generalized tonic-clonic seizure followed by post-ictal confusion and neuropsychiatric behaviors. The diagnosis is PRES. Investigations showed uterine cervical region with multiple liver metastasis complicated with hypercalcemia, elevated intact parathyroid hormone. Further pathology concluded as a poorly differentiated adenocarcinoma of the endometrium with neuroendocrine differentiation and immunoreactive for PTH. The patient's neurologic manifestations had resolved. Serum free calcium level and intact-PTH had declined after first course of definitive chemoradiation. CONCLUSION: Immunostaining of the tumor tissue can be used to estimate the ectopic PTH production within the tumor cells. Early detection and appropriate clinical treatment hold the potential to improve the prognosis of refractory hypercalcemia and hypercalcemia related PRES. Keyword: Posterior reversible encephalopathy syndrome; hypercalcemia; intact-parathyroid hormone; parathyroid hormone-related peptide; neuroendocrine carcinoma of endometrium.

Wnt activation promotes memory T cell polyfunctionality via epigenetic regulator PRMT1.

T cell polyfunctionality is a hallmark of protective immunity against pathogens and cancer, yet the molecular mechanism governing it remains mostly elusive. We found that canonical Wnt agonists inhibited human memory CD8+ T cell differentiation while simultaneously promoting the generation of highly polyfunctional cells. Downstream effects of Wnt activation persisted after removal of the drug, and T cells remained polyfunctional following subsequent cell division, indicating the effect is epigenetically regulated. Wnt activation induced a gene expression pattern that is enriched with stem cell-specific gene signatures and upregulation of protein arginine methyltransferase 1 (PRMT1), a known epigenetic regulator. PRMT1+CD8+ T cells are associated with enhanced polyfunctionality, especially the ability to produce IL-2. In contrast, inhibition of PRMT1 ameliorated the effects of Wnt on polyfunctionality. Chromatin immunoprecipitation revealed that H4R3me2a, a permissive transcription marker mediated by PRMT1, increased at the IL-2 promoter loci following Wnt activation. In vivo, Wnt-treated T cells exhibited superior polyfunctionality and persistence. When applied to cytomegalovirus (CMV) donor-seropositive, recipient-seronegative patients (D+/R-) lung transplant patient samples, Wnt activation enhanced CMV-specific T cell polyfunctionality, which is important in controlling CMV diseases. These findings reveal a molecular mechanism governing T cell polyfunctionality and identify PRMT1 as a potential target for T cell immunotherapy.

Germanium-Titanium-π Polymer Composites as Functional Textiles for Clinical Strategy to Evaluate Blood Circulation Improvement and Sexual Satisfaction.

By continuously enhancing the blood flow, far-infrared (FIR) textile is anticipated to be a potential non-pharmacological therapy in patients with peripheral vascular disorders, for instance, patients with end-stage renal disease (ESRD) undergoing hemodialysis (HD) and experiencing vasculogenic erectile dysfunction (VED). Hence, we manufactured a novel polymer composite, namely, germanium-titanium-π (Ge-Ti-π) textile and aimed to evaluate its characteristics and quality. We also investigated the immediate and long-term effects of the textile on patients with ESRD undergoing HD and experiencing VED. The Ge-Ti-π textile was found to have 0.93 FIR emissivity, 3.05 g/d strength, and 18.98% elongation. The results also showed a 51.6% bacteria reduction and negative fungal growth. On application in patients receiving HD, the Ge-Ti-π textile significantly reduced the limb numbness/pain (p < 0.001) and pain score on the visual analog scale (p < 0.001). Moreover, the Doppler ultrasound assessment data indicated a significant enhancement of blood flow in the right hand after 1 week of Ge-Ti-π textile treatment (p < 0.041). In VED patients, the Ge-Ti-π underpants treatment significantly improved the quality of sexual function and increased the average penile blood flow velocity after 3 months of the treatment. Our study suggests that the Ge-Ti-π textile could be beneficial for patients with blood circulation disorders.

Optical measurement in a curved optical medium with optical birefringence and anisotropic absorption.

The planar optical mediums with properties of either birefringence (i.e., waveplates) or anisotropic absorption (i.e., polarizers) are well studied. However, how a beam propagates in a birefringent curved medium with anisotropic absorption, especially for curved-sheet polarizers, still needs to be investigated. In this paper, we study optical wave propagation through a curved-birefringent medium with anisotropic absorption. We built an optical model based on the Mueller matrix to predict the spatial distributions in light intensity and polarization when light propagates in a curved-birefringent medium with anisotropic absorption. To demonstrate how to use the optical model, the experiments based on ellipsometry are also performed. The impact of this study is to analyze the light propagation in birefringent-curved medium with anisotropic absorption, which could affect the performance of curved liquid crystal devices with curved polarizers, such as curved liquid crystal displays (LCDs), flexible LCDs, and flexible LC lenses.

Electrically tunable polarization independent liquid crystal lenses based on orthogonally anisotropic orientations on adjacent micro-domains.

Polarization dependency is an intrinsic property of liquid crystals (LC) devices but major problem is optical efficiency. We demonstrated a polarization independent liquid crystal phase modulation based on the orthogonal nematic LC (OLC) mode wherein the optics axes of nematic liquid crystal molecules are set orthogonally to adjacent sub-domains for the first time. Such an OLC mode includes sub-domain with anisotropic orientations but collectively presents a capability of a polarizer-free optical phase modulation. An OLC mode cell provides a tunable optical phase of ∼3.35π radians for unpolarized light and different linearly polarized light. Among the polarizer-free LC mode, the proposed OLC mode is single-layered with large tunable optical phase. We also demonstrated a polarizer-free LC micro-lens. We expect this novel LC mode provide alternatives technology roadmap for upcoming optical applications, such as electrically tunable ophthalmic lenses and optical systems for augmented reality.

Lingual thyroid with severe hypothyroidism: A case report.

INTRODUCTION: Ectopic thyroid tissue presenting at the base of the tongue, called lingual thyroid, is a clinical rarity. Clinical presentation varies depending upon either the severity of regional symptoms associated with the enlargement of gland size, or the features related to thyroid dysfunction. PATIENT CONCERNS: We reported a case of a 29-year-old female who presented with symptoms of easy fatigue and depression for 3 months. DIAGNOSIS: After a series of diagnostic workup, the lingual thyroid with severe hypothyroidism was diagnosed. INTERVENTION AND OUTCOME: She received conservative treatment with thyroid hormone replacement and the symptoms improved significantly. LESSONS: Lingual thyroid is a rare entity that needs careful diagnostic workup including clinical examination, biochemical tests, imaging methods such as ultrasonography, scintigraphy, computed tomography, magnetic resonance imaging, and fine-needle aspiration cytology to plan the management. Lingual thyroid with hypothyroidism and no neck regional symptoms can be conservatively treated and requires regular follow-up for the prevention of potential risk of malignant transformation.