Global Continuum and Multiple Positive Solutions to a P-Laplacian Boundary-Value Problem

A p-Laplacian boundary-value problem with positive nonlinearity is considered. The existence of a continuum of positive solutions emanating from (lambda, u) = (0, 0) is shown, and it can be extended to lambda = infinity. Under an additional condition on the nonlinearity, it is shown that the positive solution is unique for any lambda \u3e 0; thus the continuum C is indeed a continuous curve globally defined for all lambda \u3e 0. In addition, by the upper and lower solutions method, existence of three positive solutions is established under some conditions on the nonlinearity

Exact multiplicity of positive solutions for a p-Laplacian equation with positive convex nonlinearity

A p-Laplacian nonlinear elliptic equation with positive and p-superlinear nonlinearity and Dirichlet boundary condition is considered. We first prove the existence of two positive solutions when the spatial domain is symmetric or strictly convex by using a priori estimates and topological degree theory. For the ball domain in R-N with N \u3e= 4 and the case that 1 \u3c p \u3c 2, we prove that the equation has exactly two positive solutions when a parameter is less than a critical value. Bifurcation theory and linearization techniques are used in the proof of the second result. (C) 2015 Elsevier Inc. All rights reserved

Ultrasensitive, high-dynamic-range and broadband strain sensing by time-of-flight detection with femtosecond-laser frequency combs

Ultrahigh-resolution optical strain sensors provide powerful tools in various scientific and engineering fields, ranging from long-baseline interferometers to civil and aerospace industries. Here we demonstrate an ultrahigh-resolution fibre strain sensing method by directly detecting the time-of-flight (TOF) change of the optical pulse train generated from a free-running passively mode-locked laser (MLL) frequency comb. We achieved a local strain resolution of 18 p{\epsilon}/Hz1/2 and 1.9 p{\epsilon}/Hz1/2 at 1 Hz and 3 kHz, respectively, with largedynamic range of >154 dB at 3 kHz. For remote-point sensing at 1-km distance, 80 p{\epsilon}/Hz1/2 (at 1 Hz) and 2.2 p{\epsilon}/Hz1/2 (at 3 kHz) resolution is demonstrated. While attaining both ultrahigh resolution and large dynamic range, the demonstrated method can be readily extended for multiple-point sensing as well by taking advantage of the broad optical comb spectra. These advantages may allow various applications of this sensor in geophysical science, structural health monitoring, and underwater science.Comment: 20 pages, 4 figure

In vivo Imaging and Drug Storage by Quantum-Dot-Conjugated Carbon Nanotubes

A specially designed carbon nanotube (CNT) is developed for use in the early detection and treatment of cancer. The key functionalities for biomedical diagnosis and drug delivery are incorporated into the CNTs. In vivo imaging of live mice is achieved by intravenously injecting quantum dot (QD)-conjugated CNT for the first time. With near infrared emission around 752 nm, the CNT with surface-conjugated QD (CNT-QD) exhibit a strong luminescence for non-invasive optical in vivo imaging. CNT surface modification is achieved by a plasma polymerization approach that deposited ultra-thin acrylic acid or poly(lactic- co -glycolic acid) (PLGA) films (∼3 nm) onto the nanotubes. The anticancer agent paclitaxel is loaded at 112.5 ± 5.8 µg mg −1 to PLGA-coated CNT. Cytotoxicity of this novel drug delivery system is evaluated in vitro using PC-3MM2 human prostate carcinoma cells and quantified by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The in vivo distribution determined by inductively coupled plasma mass spectrometry (ICP-MS) indicates CNT-QD uptake in various organs of live animals.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/60988/1/2489_ftp.pd

Design of grating Al2O3 passivation structure optimized for high-efficiency Cu(In,Ga)Se2 solar cells

In this paper, we propose an optimized structure of thin Cu(In,Ga)Se2 (CIGS) solar cells with a grating aluminum oxide (Al2 O3) passivation layer (GAPL) providing nano-sized contact openings in order to improve power conversion efficiency using optoelectrical simulations. Al2 O3 is used as a rear surface passivation material to reduce carrier recombination and improve reflectivity at a rear surface for high efficiency in thin CIGS solar cells. To realize high efficiency for thin CIGS solar cells, the optimized structure was designed by manipulating two structural factors: the contact opening width (COW) and the pitch of the GAPL. Compared with an unpassivated thin CIGS solar cell, the efficiency was improved up to 20.38% when the pitch of the GAPL was 7.5–12.5 µm. Furthermore, the efficiency was improved as the COW of the GAPL was decreased. The maximum efficiency value occurred when the COW was 100 nm because of the effective carrier recombination inhibition and high reflectivity of the Al2 O3 insulator passivation with local contacts. These results indicate that the designed structure has optimized structural points for high-efficiency thin CIGS solar cells. Therefore, the photovoltaic (PV) generator and sensor designers can achieve the higher performance of photosensitive thin CIGS solar cells by considering these results. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.1

Sequencing and characterization of Varicella-Zoster virus vaccine strain SuduVax

<p>Abstract</p> <p>Background</p> <p>Varicella-zoster virus (VZV) causes chickenpox in children and shingles in older people. Currently, live attenuated vaccines based on the Oka strain are available worldwide. In Korea, an attenuated VZV vaccine has been developed from a Korean isolate and has been commercially available since 1994. Despite this long history of use, the mechanism for the attenuation of the vaccine strain is still elusive. We attempted to understand the molecular basis of attenuation mechanism by full genome sequencing and comparative genomic analyses of the Korean vaccine strain SuduVax.</p> <p>Results</p> <p>SuduVax was found to contain a genome that was 124,759 bp and possessed 74 open reading frames (ORFs). SuduVax was genetically most close to Oka strains and these Korean-Japanese strains formed a strong clade in phylogenetic trees. SuduVax, similar to the Oka vaccine strains, underwent T- > C substitution at the stop codon of ORF0, resulting in a read-through mutation to code for an extended form of ORF0 protein. SuduVax also shared certain deletion and insertion mutations in ORFs 17, 29, 56 and 60 with Oka vaccine strains and some clinical strains.</p> <p>Conclusions</p> <p>The Korean VZV vaccine strain SuduVax is genetically similar to the Oka vaccine strains. Further comparative genomic and bioinformatics analyses will help to elucidate the molecular basis of the attenuation of the VZV vaccine strains.</p

Flexible Cu2ZnSn(S,Se)4 solar cells with over 10% efficiency and methods of enlarging the cell area

For kesterite copper zinc tin sulfide/selenide (CZTSSe) solar cells to enter the market, in addition to efficiency improvements, the technological capability to produce flexible and large-area modules with homogeneous properties is necessary. Here, we report a greater than 10% efficiency for a cell area of approximately 0.5 cm2 and a greater than 8% efficiency for a cell area larger than 2 cm2 of certified flexible CZTSSe solar cells. By designing a thin and multi-layered precursor structure, the formation of defects and defect clusters, particularly tin-related donor defects, is controlled, and the open circuit voltage value is enhanced. Using statistical analysis, we verify that the cell-to-cell and within-cell uniformity characteristics are improved. This study reports the highest efficiency so far for flexible CZTSSe solar cells with small and large areas. These results also present methods for improving the efficiency and enlarging the cell area. © 2019, The Author(s).1

A multidimensional platform for the purification of non-coding RNA species

A renewed interest in non-coding RNA (ncRNA) has led to the discovery of novel RNA species and post-transcriptional ribonucleoside modifications, and an emerging appreciation for the role of ncRNA in RNA epigenetics. Although much can be learned by amplification-based analysis of ncRNA sequence and quantity, there is a significant need for direct analysis of RNA, which has led to numerous methods for purification of specific ncRNA molecules. However, no single method allows purification of the full range of cellular ncRNA species. To this end, we developed a multidimensional chromatographic platform to resolve, isolate and quantify all canonical ncRNAs in a single sample of cells or tissue, as well as novel ncRNA species. The applicability of the platform is demonstrated in analyses of ncRNA from bacteria, human cells and plasmodium-infected reticulocytes, as well as a viral RNA genome. Among the many potential applications of this platform are a system-level analysis of the dozens of modified ribonucleosides in ncRNA, characterization of novel long ncRNA species, enhanced detection of rare transcript variants and analysis of viral genomes.Singapore-MIT Alliance for Research and TechnologyNational Institute of Environmental Health Sciences (ES017010)National Institute of Environmental Health Sciences (ES002109