Time-resolved photoluminescence of the size-controlled ZnO nanorods

Size dependence of the time-resolved photoluminescence (TRPL) has been investigated for the ZnO nanorods fabricated by catalyst-free metalorganic chemical vapor deposition. The nanorods have a diameter of 35 nm and lengths in the range of 150 nm to 1.1 mum. The TRPL decay rate decreases monotonically as the length of the nanorods increases in the range of 150 to 600 nm. Decrease of the radiative decay rate of the exciton-polariton has been invoked to account for the results

Time resolved photoluminescence of the size controlled ZnO nanorods

Size dependence of the time-resolved photoluminescence (TRPL) has been investigated for the ZnO nanorods fabricated by catalyst-free metalorganic chemical vapor deposition. The nanorods have a diameter of 35 nm and lengths in the range of 150 nm to 1.1 mum. The TRPL decay rate decreases monotonically as the length of the nanorods increases in the range of 150 to 600 nm. Decrease of the radiative decay rate of the exciton-polariton has been invoked to account for the results

Development of brain PET using GAPD arrays

Purpose: In recent times, there has been great interest in the use of Geiger-mode avalanche photodiodes (GAPDs) as scintillator readout in positron emission tomography (PET) detectors because of their advantages, such as high gain, compact size, low power consumption, and magnetic field insensitivity. The purpose of this study was to develop a novel PET system based on GAPD arrays for brain imaging. Methods: The PET consisted of 72 detector modules arranged in a ring of 330 mm diameter. Each PET module was composed of a 4 Â 4 matrix of 3 Â 3 Â 20 mm 3 cerium-doped lutetium yttrium orthosilicate (LYSO) crystals coupled with a 4 Â 4 array three-side tileable GAPD. The signals from each PET module were fed into preamplifiers using a 3 m long flat cable and then sent to a position decoder circuit (PDC), which output a digital address and an analog pulse of the interacted channel among 64 preamplifier signals tranmitted from four PET detector modules. The PDC outputs were fed into field programmable gate array (FPGA)-embedded data acquisition (DAQ) boards. The analog signal was then digitized, and arrival time and energy of the signal were calculated and stored. Results: The energy and coincidence timing resolutions measured for 511 keV gamma rays were 18.4 6 3.1% and 2.6 ns, respectively. The transaxial spatial resolution and sensitivity in the center of field of view (FOV) were 3.1 mm and 0.32% cps/Bq, respectively. The rods down to a diameter of 2.5 mm were resolved in a hot-rod phantom image, and activity distribution patterns between the white and gray matters in the Hoffman brain phantom were well imaged. Conclusions: Experimental results indicate that a PET system can be developed using GAPD arrays and the GAPD-based PET system can provide high-quality PET imaging

Wide-band CMOS loop-through amplifier for cable TV tuner

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Enhancing plant immunity by expression of pathogen-targeted CRISPR-Cas9 in plants

Recent studies showed that CRISPR nucleases can boost plant immunity against infected virus by inducing the cleavage of viral dsDNA intermediate in a host plant. Here, we demonstrate that CRISPR-Cas9 can also improve plant resistance against a bacterial pathogen, Pseudomonas syringae, when sgRNAs that selectively target the bacterial genome are either transiently or constitutively expressed in plants. Our findings indicate that plant-expressed CRISPR-Cas9 components can transport into bacterial cells and disrupt the bacterial genome, suggesting a novel defense strategy against pathogens in plants, which could be widely applied regardless of the bacterial species

Performance Comparison of CdTe:Na, CdTe:As, and CdTe:P Single Crystals for Solar Cell Applications

We compared thermal stability, open-circuit voltage, short-circuit current, and fill factor values of single-crystal Cadmium telluride (CdTe) grown using the vertical Bridgman (VB) technique and doped with group V elements (phosphorus and arsenic), and group Ⅰ element (sodium), followed by an annealing process. The sodium-doped CdTe maintained a hole density of 1016 cm−3 or higher; after annealing for a long time, this decreased to 1015 cm−3 or less. The arsenic-doped CdTe maintained a hole density of approximately 1016 cm−3 even after the annealing process; however its bulk minority carrier lifetime decreased by approximately 10%. The phosphorus-doped CdTe maintained its properties after the annealing process, ultimately achieving a hole density of ~1016 cm−3 and a minority carrier lifetime of ~40 ns. The characteristics of a single-crystal solar cell were evaluated using a solar cell device that contained single-crystal CdTe with various dopants. The sodium-doped sample exhibited poor interfacial properties, and its performance decreased rapidly during annealing. The samples doped with group V elements exhibited stable characteristics even during long-term annealing. We concluded, therefore, that group V elements dopants are more suitable for CdTe single-crystal-based solar cell applications involving thermal stress conditions, such as space missions or extreme fabrication temperature environments

PE-Designer and PE-Analyzer: web-based design and analysis tools for CRISPR prime editing

Prime editing technology is capable of generating targeted insertions, deletions, and base conversions. However, the process of designing prime editing guide RNAs (pegRNAs), which contain a primer binding site and a reverse-transcription template at the 3' end, is more complex than that for the single guide RNAs used with CRISPR nucleases or base editors. Furthermore, the assessment of high-throughput sequencing data after prime editors (PEs) have been employed should consider the unique feature of PEs; thus, pre-existing assessment tools cannot directly be adopted for PEs. Here, we present two user-friendly web-based tools for PEs, named PE-Designer and PE-Analyzer. PE-Designer, a dedicated tool for pegRNA selection, provides all possible target sequences, pegRNA extension sequences, and nicking guide RNA sequences together with useful information, and displays the results in an interactive image. PE-Analyzer, a dedicated tool for PE outcome analysis, accepts high-throughput sequencing data, summarizes mutation-related information in a table, and provides interactive graphs. PE-Analyzer was mainly written using JavaScript so that it can analyze several data sets without requiring that huge sequencing data (>100MB) be uploaded to the server, reducing analysis time and increasing personal security.

Adenine base editor engineering reduces editing of bystander cytosines

Adenine base editors (ABEs) catalyze specific A-to-G conversions at genomic sites of interest. However, ABEs also induce cytosine deamination at the target site. To reduce the cytosine editing activity, we engineered a commonly used adenosine deaminase, TadA7.10, and found that ABE7.10 with a D108Q mutation in TadA7.10 exhibited tenfold reduced cytosine deamination activity. The D108Q mutation also reduces cytosine deamination activity in two recently developed high-activity versions of ABE, ABE8e and ABE8s, and is compatible with V106W, a mutation that reduces off-target RNA editing. ABE7.10 containing a P48R mutation displayed increased cytosine deamination activity and a substantially reduced adenine editing rate, yielding a TC-specific base editing tool for TC-to-TT or TC-to-TG conversions that broadens the utility of base editors. Engineered variants of adenine base editors have reduced cytosine base editing or a specific C-to-G base editing activity.

NFAT1 and NFκB regulates expression of the common γ-chain cytokine receptor in activated T cells

Abstract Introduction Cytokines of the common γ chain (γc) family are critical for the development, differentiation, and survival of T lineage cells. Cytokines play key roles in immunodeficiencies, autoimmune diseases, allergies, and cancer. Although γc is considered an assistant receptor to transmit cytokine signals and is an indispensable receptor in the immune system, its regulatory mechanism is not yet well understood. Objective This study focused on the molecular mechanisms that γc expression in T cells is regulated under T cell receptor (TCR) stimulation. Methods The γc expression in TCR-stimulated T cells was determined by flow cytometry, western blot and quantitative RT-PCR. The regulatory mechanism of γc expression in activated T cells was examined by promoter-luciferase assay and chromatin immunoprecipitation assays. NFAT1 and NFκB deficient cells generated using CRISPR-Cas9 and specific inhibitors were used to examine their role in regulation of γc expression. Specific binding motif was confirmed by γc promotor mutant cells generated using CRISPR-Cas9. IL-7TgγcTg mice were used to examine regulatory role of γc in cytokine signaling. Results We found that activated T cells significantly upregulated γc expression, wherein NFAT1 and NFκB were key in transcriptional upregulation via T cell receptor stimulation. Also, we identified the functional binding site of the γc promoter and the synergistic effect of NFAT1 and NFκB in the regulation of γc expression. Increased γc expression inhibited IL-7 signaling and rescued lymphoproliferative disorder in an IL-7Tg animal model, providing novel insights into T cell homeostasis. Conclusion Our results indicate functional cooperation between NFAT1 and NFκB in upregulating γc expression in activated T cells. As γc expression also regulates γc cytokine responsiveness, our study suggests that γc expression should be considered as one of the regulators in γc cytokine signaling and the development of T cell immunotherapies. Video Abstrac