Camera for QUasars in EArly uNiverse (CQUEAN)

We describe the overall characteristics and the performance of an optical CCD camera system, Camera for QUasars in EArly uNiverse (CQUEAN), which is being used at the 2.1 m Otto Struve Telescope of the McDonald Observatory since 2010 August. CQUEAN was developed for follow-up imaging observations of red sources such as high redshift quasar candidates (z >= 5), Gamma Ray Bursts, brown dwarfs, and young stellar objects. For efficient observations of the red objects, CQUEAN has a science camera with a deep depletion CCD chip which boasts a higher quantum efficiency at 0.7 - 1.1 um than conventional CCD chips. The camera was developed in a short time scale (~ one year), and has been working reliably. By employing an auto-guiding system and a focal reducer to enhance the field of view on the classical Cassegrain focus, we achieve a stable guiding in 20 minute exposures, an imaging quality with FWHM >= 0.6" over the whole field (4.8' * 4.8'), and a limiting magnitude of z = 23.4 AB mag at 5-sigma with one hour total integration time.Comment: Accepted for publication in PASP. 26 pages including 5 tables and 24 figure

Disruption of Microtubules Sensitizes the DNA Damage-induced Apoptosis Through Inhibiting Nuclear Factor κB (NF-κB) DNA-binding Activity

The massive reorganization of microtubule network involves in transcriptional regulation of several genes by controlling transcriptional factor, nuclear factor-kappa B (NF-κB) activity. The exact molecular mechanism by which microtubule rearrangement leads to NF-κB activation largely remains to be identified. However microtubule disrupting agents may possibly act in synergy or antagonism against apoptotic cell death in response to conventional chemotherapy targeting DNA damage such as adriamycin or comptothecin in cancer cells. Interestingly pretreatment of microtubule disrupting agents (colchicine, vinblastine and nocodazole) was observed to lead to paradoxical suppression of DNA damage-induced NF-κB binding activity, even though these could enhance NF-κB signaling in the absence of other stimuli. Moreover this suppressed NF-κB binding activity subsequently resulted in synergic apoptotic response, as evident by the combination with Adr and low doses of microtubule disrupting agents was able to potentiate the cytotoxic action through caspase-dependent pathway. Taken together, these results suggested that inhibition of microtubule network chemosensitizes the cancer cells to die by apoptosis through suppressing NF-κB DNA binding activity. Therefore, our study provided a possible anti-cancer mechanism of microtubule disrupting agent to overcome resistance against to chemotherapy such as DNA damaging agent

Circulating tumor cells detected by lab-on-adisc: Role in early diagnosis of gastric cancer

[Background] The use of circulating tumor cells (CTCs) as an early diagnostic biomarker and prognostic indicator after surgery or chemotherapy has been suggested for various cancers. This study aimed to evaluate CTCs in patients who underwent gastrectomy for gastric cancer and to explore their clinical usefulness in the early diagnosis of gastric cancer. [Methods] A total of 116 patients with gastric cancer who underwent gastrectomy and 31 healthy volunteers were prospectively included between 2014 and 2015. Peripheral blood samples were collected before gastrectomy, and CTCs were examined using a centrifugal microfluidic system with a new fluid-assisted separation technique. [Results] After creating a receiver operating characteristic curve to identify the discriminative CTC value needed differentiate patients with gastric cancer from healthy volunteers, sensitivity and specificity were nearly optimized at a CTC threshold of 2 per 7.5 mL of blood. Of the 102 persons with a CTC level >= 2 per 7.5 mL of blood, 99 (97.1%) had gastric cancer, and of the 45 persons with a CTC level <2 per 7.5 mL of blood, 28 (62.2%) were healthy controls. Accordingly, the sensitivity and specificity for the differentiation of patients with gastric cancer from healthy controls were 85.3% and 90.3%, respectively. However, the presence of CTCs was not associated with any clinicopathologic features such as staging, histologic type, or mucin phenotype. [Conclusion] Although we could not prove the clinical feasibility of CTCs for gastric cancer staging, our results suggest a potential role of CTCs as an early diagnostic biomarker of gastric cancer

Retrospective evaluation of whole exome and genome mutation calls in 746 cancer samples

Funder: NCI U24CA211006Abstract: The Cancer Genome Atlas (TCGA) and International Cancer Genome Consortium (ICGC) curated consensus somatic mutation calls using whole exome sequencing (WES) and whole genome sequencing (WGS), respectively. Here, as part of the ICGC/TCGA Pan-Cancer Analysis of Whole Genomes (PCAWG) Consortium, which aggregated whole genome sequencing data from 2,658 cancers across 38 tumour types, we compare WES and WGS side-by-side from 746 TCGA samples, finding that ~80% of mutations overlap in covered exonic regions. We estimate that low variant allele fraction (VAF < 15%) and clonal heterogeneity contribute up to 68% of private WGS mutations and 71% of private WES mutations. We observe that ~30% of private WGS mutations trace to mutations identified by a single variant caller in WES consensus efforts. WGS captures both ~50% more variation in exonic regions and un-observed mutations in loci with variable GC-content. Together, our analysis highlights technological divergences between two reproducible somatic variant detection efforts

Effects of Interface States on Electrical Characteristics of Feedback Field-Effect Transistors

In this study, we examine the effect of interface trap states on the electrical characteristics of single-gated feedback field-effect transistors (FBFETs) using a commercially available computer-aided design simulation package. Interface trap states exist between the channels and the oxide layers, and these trap states act as acceptor-like trap states in regions of higher energy than the intrinsic Fermi energy ( $E_{\mathrm {i}}$ ) and as donor-like trap states in regions of lower energy than $E_{\mathrm {i}}$ in the energy band. The density distribution peaks at $E_{\mathrm {i}}$ + 0.28 eV for the acceptor-like trap states and at $E_{\mathrm {i}}$ &#x2013; 0.28 eV for the donor-like trap states. The occupation mechanism of these trap states is analyzed by the density of the interface states and trapped charges, the energy band diagram, and the current-voltage curves. In n-channel (p-channel) FBFETs, the latch-up voltage varies by approximately 0.01 V as the acceptor-like (donor-like) trap states increase, whereas the effect of the donor-like (acceptor-like) trap states is negligible. Moreover, the FBFETs exhibit an operating speed of 4 ns and retention time of 900 s during a memory operation, despite the existence of the interface states

Logic and memory functions of an inverter comprising reconfigurable double gated feedback field effect transistors

Abstract In this study, we propose an inverter consisting of reconfigurable double-gated (DG) feedback field-effect transistors (FBFETs) and examine its logic and memory operations through a mixed-mode technology computer-aided design simulation. The DG FBFETs can be reconfigured to n- or p-channel modes, and these modes exhibit an on/off current ratio of ~ 1012 and a subthreshold swing (SS) of ~ 0.4 mV/dec. Our study suggests the solution to the output voltage loss, a common problem in FBFET-based inverters; the proposed inverter exhibits the same output logic voltage as the supply voltage in gigahertz frequencies by applying a reset operation between the logic operations. The inverter retains the output logic ‘1’ and ‘0’ states for ~ 21 s without the supply voltage. The proposed inverter demonstrates the promising potential for logic-in-memory application

WR-3.4 Overmoded Waveguide Module for the Packaging of a Linear Integrated-Circuit Array

The performance of WR-3.4 overmoded waveguide modules containing a linear array of discrete terahertz integrated circuits is presented to verify a new power-combining technique. Custom-designed thru-line IC chips that include back-to-back broadband antenna transitions were fabricated with an area of 390 × 750 mm2 for waveguide packaging. Multiple array modules were assembled to verify the repeatability in performance. The array modules exhibited almost identical amounts of insertion losses compared with single-element modules, showing the best insertion loss of 2.6 dB over a 1 dB bandwidth of 95 GHz

WR-3.4 Overmoded Waveguide Module for the Packaging of a Linear Integrated-Circuit Array

The performance of WR-3.4 overmoded waveguide modules containing a linear array of discrete terahertz integrated circuits is presented to verify a new power-combining technique. Custom-designed thru-line IC chips that include back-to-back broadband antenna transitions were fabricated with an area of 390 &times; 750 mm2 for waveguide packaging. Multiple array modules were assembled to verify the repeatability in performance. The array modules exhibited almost identical amounts of insertion losses compared with single-element modules, showing the best insertion loss of 2.6 dB over a 1 dB bandwidth of 95 GHz

Bidirectional Synaptic Operations of Triple‐Gated Silicon Nanosheet Transistors with Reconfigurable Memory Characteristics

Abstract In this study, a triple‐gated transistor with a p+‐i‐n+ silicon nanosheet (NS) is proposed as a single synaptic device, and bidirectional synaptic functions are realized using reconfigurable memory characteristics. The triple‐gated NS transistor features steep switching and bistable characteristics with a subthreshold swing below 5 mV dec−1 and an ON/OFF current ratio of ≈5 × 106 for both the n‐ and p‐channel modes. This transistor exhibits electrically symmetric reconfigurable memory characteristics with an ON current ratio of 1.02 for the n‐ and p‐channel modes. Moreover, the bidirectional synaptic weight updates of binarized spike‐timing‐dependent plasticity learning are successfully performed in a single transistor. This study demonstrates the potential of a triple‐gated NS transistor for achieving compact synaptic arrays in large‐scale silicon‐based neuromorphic computing systems

Reconfigurable Logic‐In‐Memory Cell Comprising Triple‐Gated Feedback Field‐Effect Transistors

Abstract A reconfigurable logic‐in‐memory (R‐LIM) cell performs logic‐in‐memory functions as well as reconfigurable logic gates. The R‐LIM cell is constructed with triple‐gated (TG) feedback field‐effect transistors (FBFETs) that are reconfigured in n‐channel or p‐channel modes via electrostatic doping. Each TG FBFET has one control gate electrode and two program‐gate electrodes that determine the channel mode. Their reconfigurability enables the symmetrical operation of the n‐channel and p‐channel modes through an on‐current ratio of 1:04. Furthermore, the R‐LIM cell performs eight Boolean logic operations, storing the logic outputs for ≈100 s under zero‐bias conditions. The R‐LIM cell is useful for developing in‐memory computing systems with high energy efficiency and functional logic