We designed and fabricated silicon positive-intrinsic-negative (PIN) photodiodes coupled with a scintillator for radiation detection. The photodiodes were fabricated on an
n
-type double-sided ...polished silicon wafer with a diameter of 6-in., a high resistivity (<5kΩ·cm), and a orientation. To increase the quantum efficiency (QE) of the photodiode, an anti-reflection coating (ARC) was provided on the side where light entered. It is difficult to realize an ARC with an uniform thickness in the sensor fabrication process. The effect of changes in the ARC thickness on the QE of the fabricated sensors was studied in detail. We measured the electrical characteristics and compared their quantum efficiencies as a function of the incident light wavelength for the photodiodes with different ARC thicknesses. In this paper, we present the design of the photodiodes and their measured electrical characteristics and photo-responses for different ARC thicknesses. From measurements of the wavelength-dependent QE, we determined the refractive index of the ARC layer to be 2.25 ± 0.15. The ARC layer improved the QE up to 56% and 63% at the wavelengths of 550 and 475 nm, which correspond to the wavelengths of the scintillation light from CsI(Tl) and CdWO
4
, respectively.
Nephrotoxicity is one of the major side effects that limit the use of cisplatin in cancer therapy. Cisplatin-induced apoptosis in renal cells is associated with reactive oxygen species (ROS)-mediated ...p53 activation. Licorice (Glycyrrhiza uralensis Fischer) is one of the most widely used medicinal herbs in Korea, China and Japan. The aim of the study was to evaluate the protective effects of licorice extract (LE) and its active compound glycyrrhizic acid (GA) against cisplatin-induced nephrotoxicity in human renal proximal tubular epithelial (HK-2) cells.
HK-2 cells were pretreated with LE or GA for 1 h and then treated with 40 μM of cisplatin for indicated times under the serum-free condition. Cell viability was evaluated by MTT assay. Apoptosis was evaluated by flow cytometric analysis and caspase-3 activity. The intracellular ROS levels were determined by DCFH-DA assay. The expression and phosphorylation levels of protein were evaluated by Western blot and densitometry analysis.
When treating HK-2 cells with LE or GA, both of them alleviated cisplatin-induced cytotoxicity and apoptosis. LE and GA inhibited caspase-3 activity and polymerase (PARP) cleavage in cisplatin-treated cells. LE and GA also inhibited p53 expression and its phosphorylation as well as ROS production in cells exposed to cisplatin. Meanwhile, LE and GA enhanced cisplatin-induced p21 expression, which then led to S-phase arrest in cell cycle and limited cell growth. Presumably, increased p21 expression may contribute to cellular prevention from cisplatin-induced apoptosis, because p21 is the key molecule to cytoprotection during cisplatin-induced nephrotoxicity.
These results suggest that LE and GA ameliorate cisplatin-induced apoptosis through reduction of ROS-mediating p53 activation and promotion of p21 expression in HK-2 cells.
In search of readily available and relatively inexpensive materials for phosphorus removal, waste oyster shell is a waste product from oyster-culturing farm and also presents a major disposal problem ...in itself. Activated oyster shell produced by pyrolysis at 750 °C exhibits promising performance as a suitable substance for phosphorus removal. The capacity of the activated oyster shell, in terms of equivalents of OH
− per gram of material, is about 80% than that of calcium hydroxide. However, the granular nature of activated oyster shell (AOS) makes it much easier to handle than lime. This would be a very important advantage for treatment facilities that cannot afford specialized powder handling facilities necessary for lime. Another advantage of AOS is its time-release properties, which can allow it to be added to reactors intermittently and still achieve consistent phosphate precipitation. Distribution of phosphate after contact with AOS indicates that adsorption does not play a significant role in phosphate removal with AOS. Rather, it appears that the phosphate is precipitated in the presence of Ca
2+ and high pH as a key mechanism. Since it is produced from a waste product of mariculture, AOS is a sustainable precipitant for phosphate removal.
TRAIL (tumor necrosis factor-related apoptosis-inducing ligand) is a potent inducer of apoptosis in tumor cells and holds a promise as a therapeutic agent against cancer. To elucidate the death ...signaling evoked by TRAIL, we performed a functional genetic screening and rescued TRAIL-resistant Jurkat clones harboring ribosomal protein S6 (rpS6) cDNA in anti-sense frame. Reduction of rpS6 expression in Jurkat and HeLa cells attenuated apoptosis induced by TRAIL, but not those by other cell death signals, including tumor necrosis factor-alpha and cycloheximide, etoposide, doxorubicin, tunicamycin and staurosporine. Death receptor (DR) 4, but not DR5, was downregulated in rpS6 knockdown cells. Conversely, the sensitivity to TRAIL was increased by the ectopic expression of wild-type rpS6 and further by phospho-defective rpS6 mutant (S6-SS235,6AA), but not by phospho-mimic rpS6 mutant (S6-SS235,6DD). Also, unphosphorylatable rpS6 knock-in mouse embryo fibroblasts (rpS6(P-/-) MEFs) were more sensitive to TRAIL than control MEFs. In addition, SKHep-1 tumor cells, which express less phospho-rpS6 and are more sensitive to TRAIL than other tumor cells, became effectively desensitized to TRAIL after rpS6 knockdown. These results suggest that rpS6, especially in its unphosphorylated form, is a selective mediator of TRAIL-induced apoptosis.
A new method for object-based place recognition, where objects are used as a key intermediate representation of places, is proposed. Places are represented by object graphs and recognised from ...similarity scores between the generated graphs. An iterative Hungarian method is proposed for aligning graphs, where node and edge differences are used for measuring the similarity. The proposed technique robustly detects places without false positives, as it considers both the appearance and geometric information of places. Experiments are performed with mobile robots in indoor environments verified the effectiveness of the proposed method.
The ISS-CREAM instrument is the modified version of the Cosmic Ray Energetics And Mass (CREAM) experiment, which was flown on balloons multiple times over Antarctica and later installed on the ...International Space Station (ISS). Its primary objective is to measure the energy spectra of individual cosmic-ray elements for the charge range of Z = 1 to Z = 26, in the energy range of ∼ 1012 to ∼ 1015 eV. The instrument comprises a tungsten/scintillator calorimeter and a pixelated silicon charge detector as primary detectors to determine the energy and charge of cosmic rays. Additionally, it includes top and bottom scintillator counting detectors and a boronated scintillator detector to differentiate between electrons and hadrons for multi-TeV electron measurements. The ISS-CREAM instrument was installed on the ISS in August 2017 and operated until February 2019. This paper provides an overview of the instrument, focusing on its detectors, trigger systems, common electronics, and power systems. The paper highlights the modifications made to these components to optimize their performance for ISS operations.
Ultrasonic machining is an efficient and economical mean for precision machining of glass or ceramic materials. However, because of its complexity, the mechanism of the material removal process is ...still not well understood. Therefore, it is hard to optimize process parameters effectively. In the conventional ultrasonic machining methods, materials are removed primarily by the repeated impacts of the abrasive particles. It is time consuming and gives a relatively rough surface. In this study, in order to improve the material removal rate and the integrity of the machined surface, the chemical-assisted ultrasonic machining (CUSM) method is introduced. To obtain the chemical effects, a low concentration hydrofluoric acid solution is added to the alumina slurry. Through various experiments and comparison with conventional results, the superiority of our novel method is verified. Not only did the material removal rate increase to 200%, but also the surface roughness was improved and the machining load decreased dramatically.
The Korean Organ Transplantation Registry (KOTRY) began to register lung transplants in 2015. This is an initial report on the status of patients receiving lung transplants over the past 2 years.
We ...analyzed a total of 69 patients who received lung transplants in 2015 and 2016 and who registered with the KOTRY.
The 69 patients were treated in 5 institutions. The average (SD) donor age was 39.2 (12.6) years; there were 40 male patients. The average (SD) recipient age was 55.7 (10.0) years, and the number of male recipients was 46. A total of 66 patients underwent bilateral lung transplantation, 3 underwent single-lung transplantation, and 1 underwent simultaneous heart-lung transplantation. The most frequent indication for lung transplantation was idiopathic pulmonary fibrosis (35 patients), followed by connective tissue disease-related interstitial lung disease (9) and acute respiratory failure (8). Prior to transplantation, 23 patients required ventilator care, and 12 required extracorporeal membrane oxygenation while on the waiting list. Episodes of acute rejection during follow-up were reported in 4, 2, 1, and 1 patients at 3, 6, 9, and 12 months, respectively. Infections requiring hospitalization were reported in 27, 10, 4, and 3 patients at 3, 6, 9, and 12 months, respectively.
The establishment of KOTRY renders it possible to collect nationwide data on lung transplantation, improving research on the topic and clarifying clinical feasibility.
•Lung transplant cohort in Korea has been successfully launched since 2015.
A
bstract
The results of a search for solar axions from the Korea Invisible Mass Search (KIMS) experiment at the Yangyang Underground Laboratory are presented. Low-energy electron-recoil events would ...be produced by conversion of solar axions into electrons via the axio-electric effect in CsI(Tl) crystals. Using data from an exposure of 34,596 kg · days, we set a 90 % confidence level upper limit on the axion-electron coupling,
g
ae
, of 1
.
39 × 10
−
11
for an axion mass less than 1 keV/c
2
. This limit is lower than the indirect solar neutrino bound, and fully excludes QCD axions heavier than 0.48 eV/c
2
and 140.9 eV/c
2
for the DFSZ and KSVZ models respectively.
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