Patterning Organic Electronics Based on Nanoimprint Lithography

The objective of this work is to investigate a high-resolution patterning method based on nanoimprint lithography (NIL) for the fabrication of organic electronics. First, a high-resolution, nondestructive method was developed to pattern organic semiconductors. In this approach, a sacrificial template made of amorphous fluorinated polymer (Teflon-AF) was first patterned by NIL. Poly(3-hexylthiophene) (P3HT), a organic semiconductor, was then spin-coated on the Teflon-AF template. Removing the sacrificial template by a fluorinated solvent achieved high-resolution P3HT patterns. P3HT lines and squares of various sizes (0.35 micron to tens of microns) were obtained by this method. This process of removing the sacrificial template is fully compatible with organic semiconductors. This technique was then used to fabricate passive-matrix organic light-emitting diode (PMOLED) arrays for flat-panel display applications. Fabrication of a self-aligned bottom gate electrode for organic metal semiconductor field effect transistor (OMESFET) was also developed. This self-aligned gate allows the transistor to have a potential to operate in the high frequency. Owing to the lack of an insulating layer, OMESFET can also work in a relatively low voltage range compared to other organic field effect transistors with an insulating layer. This work also demonstrates its capability of patterning alternating self-aligned metals at the nanoscale. This research also developed a low-cost and time-saving technique to create nanostructures by transferring nanoscale polymeric sidewalls into a substrate. This polymer sidewall transfer lithographic technique can be used for generating nanostructures without advanced electron-beam lithography. Potential applications include the fabrication of nanoimprint molds with high-resolution patterns for applications in nanofluidics and nanophotonics. The polymeric sidewall is a vertically spreading layer deposited by spin-coating a polymer solution on a vertical template. Varying processing parameters such as the solution concentration or the spin-coating speed, changes the sidewall dimension, which, after pattern transfer, also changes the structure dimension on the substrate. High-resolution trenches of about 15 nm have been achieved after transferring straight-line sidewalls into the substrate. Other than straight-line sidewall patterns, this method also fabricated ring-shaped patterns including circles, squares, and concentric squares. Finally, a new structure of organic solar cells (OSCs) was investigated for increasing the solar power conversion efficiency. Although the experimental result did not meet the theoretical expectation, reasonable modifications of the device structure will be tested to achieve the goal in the future

Prognosis of Nasopharyngeal Carcinoma in the Elderly is Worse than in Younger Individuals–Experience of a Medical Institute

SummaryPurposeWe aimed to evaluate outcomes of the elderly (>65 years) by comparing with younger (<40 years) patients after treatments for nasopharyngeal carcinoma (NPC).Materials and methodsWe retrospectively obtained clinical data from charts for 23 older and 21 younger patients in whom NPC was diagnosed and who underwent curative managements during 2007 and 2011. Occurrence of local recurrence, distant metastasis, and death from any cause were recorded as endpoints. Cox proportional hazards regression was applied to determine age effects on survival risks after adjusting for the potential confounders.ResultsOlder patients more commonly received a diagnosis of chronic diseases than the younger patients (56.5% versus 23.8%, p = 0.036), whereas they were less likely to have received intensive treatments for NPC. After adjusting for medical history and neoadjuvant chemotherapy, older age was the only significant predictor in the study cohort for overall survival and progression-free survival. The adjusted hazard ratio (HR) for death from all causes in older patients was 6.3 (95% confidence interval [CI] = 1.3–30.2), and the adjusted HR for disease progression in older patients was 10.9 (95% CI = 2.3–50.6).ConclusionAging was the only independent prognostic risk factor in this study cohort. Medical history and treatment variations could not fully explain the difference in prognosis. Our results strengthen the need to ameliorate toxicities and improve supportive care for older patients with a diagnosis of NPC

Surface-Assisted Laser Desorption/Ionization Mass Spectrometry on Titania Nanotube Arrays

Titania nanotube arrays (NTA) generated from anodizing processes are tested as the substrate for surface-assisted laser desorption/ionization mass spectrometry (SALDI MS). The background generated from titania NTA is very low, making the approach suitable for the analysis of small molecules. The upper detectable mass is ∼29 kDa. Homogeneous sample deposition leads to good shot-to-shot reproducibility and suitability for quantitative analysis. Additionally, phosphopeptides can be selectively trapped on the titania NTA substrate, as illustrated by simply depositing a tryptic digest of β-casein followed by titania NTA SALDI MS analysis. The detection limit for small organics and peptides is in low fmol

GaN and InN Hexagonal Microdisks

The high-quality GaN microdisks with InGaN/GaN quantum wells (QWs) and InN microdisks were grown on γ-LiAlO2 substrates by plasma-assisted molecular beam epitaxy (PA-MBE). The samples were analysed using scanning electron microscopy, X-ray diffraction, photoluminescence, cathodoluminescence and high-resolution transmission electron microscope. The characteristics of the GaN microdisks and InN microdisks were studied and the effect of growth temperature was evaluated

San-Huang-Xie-Xin-Tang Protects against Activated Microglia- and 6-OHDA-Induced Toxicity in Neuronal SH-SY5Y Cells

San-Huang-Xie-Xin-Tang (SHXT), composed of Coptidis rhizoma, Scutellariae radix and Rhei rhizoma, is a traditional Chinese herbal medicine used to treat gastritis, gastric bleeding and peptic ulcers. This study investigated the neuroprotective effects of SHXT on microglia-mediated neurotoxicity using co-cultured lipopolysaccharide (LPS)-activated microglia-like BV-2 cells with neuroblastoma SH-SY5Y cells. Effects of SHXT on 6-hydroxydopamine (6-OHDA)-induced neurotoxicity were also examined in SH-SY5Y cells. Results indicated SHXT inhibited LPS-induced inflammation of BV-2 cells by downregulation of iNOS, NO, COX-2, PGE2, gp91phox, iROS, TNF-α, IL-1β, inhibition of IκBα degradation and upregulation of HO-1. In addition, SHXT increased cell viability and down regulated nNOS, COX-2 and gp91phox of SH-SY5Y cells co-cultured with LPS activated BV-2 cells. SHXT treatment increased cell viability and mitochondria membrane potential (MMP), decreased expression of nNOS, COX-2, gp91phox and iROS, and inhibited IκBα degradation in 6-OHDA-treated SH-SY5Y cells. SHXT also attenuated LPS activated BV-2 cells- and 6-OHDA-induced cell death in differentiated SH-SY5Y cells with db-cAMP. Furthermore, SHXT-inhibited nuclear translocation of p65 subunit of NF-κB in LPS treated BV-2 cells and 6-OHDA treated SH-SY5Y cells. In conclusion, SHXT showed protection from activated microglia- and 6-OHDA-induced neurotoxicity by attenuating inflammation and oxidative stress

Local Implicit Normalizing Flow for Arbitrary-Scale Image Super-Resolution

Flow-based methods have demonstrated promising results in addressing the ill-posed nature of super-resolution (SR) by learning the distribution of high-resolution (HR) images with the normalizing flow. However, these methods can only perform a predefined fixed-scale SR, limiting their potential in real-world applications. Meanwhile, arbitrary-scale SR has gained more attention and achieved great progress. Nonetheless, previous arbitrary-scale SR methods ignore the ill-posed problem and train the model with per-pixel L1 loss, leading to blurry SR outputs. In this work, we propose "Local Implicit Normalizing Flow" (LINF) as a unified solution to the above problems. LINF models the distribution of texture details under different scaling factors with normalizing flow. Thus, LINF can generate photo-realistic HR images with rich texture details in arbitrary scale factors. We evaluate LINF with extensive experiments and show that LINF achieves the state-of-the-art perceptual quality compared with prior arbitrary-scale SR methods.Comment: CVPR 2023 camera-ready versio

Development of a deep learning-based tool to assist wound classification

This paper presents a deep learning-based wound classification tool that can assist medical personnel in non-wound care specialization to classify five key wound conditions, namely deep wound, infected wound, arterial wound, venous wound, and pressure wound, given color images captured using readily available cameras. The accuracy of the classification is vital for appropriate wound management. The proposed wound classification method adopts a multi-task deep learning framework that leverages the relationships among the five key wound conditions for a unified wound classification architecture. With differences in Cohen's kappa coefficients as the metrics to compare our proposed model with humans, the performance of our model was better or non-inferior to those of all human medical personnel. Our convolutional neural network-based model is the first to classify five tasks of deep, infected, arterial, venous, and pressure wounds simultaneously with good accuracy. The proposed model is compact and matches or exceeds the performance of human doctors and nurses. Medical personnel who do not specialize in wound care can potentially benefit from an app equipped with the proposed deep learning model