Kinetic study of copper chemistry in chemical mechanical polishing (CMP) by an in-situ real time measurement technique

This work describes a systematic approach to study chemical reactions of copper in contact with various chemical agents and to construct a coherent etching rate model based on the fundamental chemistry. Reactions of copper with chemical agents were investigated by in-situ real time technique, quartz crystal microgravimetry (QCM). Kinetic processes were followed by QCM measurement and analyzed. A coherent etching rate formula was built based on the kinetic analysis of fundamental reactions. The requirement of repeated experiments for studying copper chemistry motivated us to develop a high throughput measurement system. We utilized surface plasmon resonance (SPR) imaging combined with multi flow channel or multi electrode for high throughput design. Fundamental physics of SPR technique and instrumental design will be provided in detail. We expect this study has an impact on relatively advanced area that utilizes copper, such as chemical mechanical polishing (CMP) in semiconductor process

Synthesis and characterization of GaP quantum dots and their application as color converters in LEDs

Department of Chemical EngineeringThe semiconductor nanomaterials have received substantial interest in the last 20 years due to the great chemical, physical properties of them. The initial studies of this field were actively conducted about containing cadmium (Cd) and lead (Pb) group II-VI semiconductors because these nanomaterials can be easily obtained by the control of nucleation and growth steps via various synthetic methods such as the hot injection method, or heating-up process. Also, these materials have tried to be used for the various applications such as LEDs, solar cell, color conversion devices, and drug delivery. However, despite the excellent optical and chemical properties of group II-VI quantum dots (QDs), applications of group II-VI nanomaterials are limited due to the toxicity of cadmium and lead. There are active researches to solve these problems through the development of synthetic methods for the non-toxic group III-V nanomaterials. However, the studies were just focused on indium phosphide (InP) nanocrystals and the materials to replace group II-V nanomaterials still lack. In this study, we presented the first results of colloidal gallium phosphide (GaP) QDs synthesis with remarkable optical properties for applying optical devices. The colloidal GaP QDs were synthesized by using the appropriate combination of precursors. The emission wavelengths of GaP QDs were mainly controlled from 400 nm to 520 nm by the ratio of precursors to surfactants. Moreover GaP QDs presented photoluminescence quantum yield (PL QY) of 35~40% and FWHM of ~75 nm in green emission. Furthermore, the GaP QDs with green emission (520 nm) were applied as color conversion materials in color conversion device with UV LED and blue LED chips. As a result, we obtained green emission by color conversion of GaP QDs and the average color conversion efficiencies were calculated in 10~15%. The performance of devices still lacked to use single color conversion materials but that was sufficient to confirm the possibility of GaP QDs as next generation color conversion materials.ope

Formin-dependent TGF-β signaling for epithelial to mesenchymal transition.

The role of distinct actin filament architectures in epithelial plasticity remains incompletely understood. We therefore determined roles for formins and the Arp2/3 complex, which are actin nucleators generating unbranched and branched actin filaments, respectively, in the process of epithelial to mesenchymal transition (EMT). In clonal lung, mammary, and renal epithelial cells, the formin activity inhibitor SMIFH2 but not the Arp2/3 complex activity inhibitor CK666 blocked EMT induced by TGF-β. SMIFH2 prevented the proximal signal of increased Smad2 phosphorylation and hence also blocked downstream EMT markers, including actin filament remodeling, decreased expression of the adherens junction protein E-cadherin, and increased expression of the matrix protein fibronectin and the transcription factor Snail. The short hairpin RNA silencing of formins DIAPH1 and DIAPH3 but not other formins phenocopied SMIFH2 effects and inhibited Smad2 phosphorylation and changes in Snail and cadherin expression. Formin activity was not necessary for the cell surface expression or dimerization of TGF-β receptors, or for nuclear translocation of TAZ, a transcription cofactor in Hippo signaling also regulated by TGF-β. Our findings reveal a previously unrecognized role for formin-dependent actin architectures in proximal TGF-β signaling that is necessary for Smad2 phosphorylation but not for cross-talk to TAZ

Increased fucosyl glycoconjugate by Mycoplasma hyopneumoniae enhances adherences of Pasteurella multocida type A in the ciliated epithelial cells of the respiratory tract

BACKGROUND: The objective of this study was to elucidate the pathogenic mechanisms of how Mycoplasma hyopneumoniae enhances secondary Pasteurella multocida type A infection which leads to porcine enzootic pneumonia in infected pigs. Sixteen pigs were experimentally infected with M. hyopneumoniae and then euthanized at 7, 14, 21 and 28 days post inoculation. In situ hybridization for M. hyopneumoniae DNA and Ulex europaeus agglutinin-I (UEA-I) lectin histochemistry for fucosyl glycoconjugate, was performed in serial lung sections to determine alteration of fucosyl glycoconjugate in M. hyopneumoniae-infected bronchial and bronchiolar epithelium. Bacterial overlay assay was performed to determine the affinity of P. multocida type A with L-fucose. RESULTS: The luminal surface of bronchial and bronchiolar epithelial cells that were stained with UEA-I always showed hybridization signals for M. hyopneumoniae but it was negative in the unaffected parts of the lung from M. hyopneumoniae-infected pigs and in lung from negative control pigs. Colocalization of M. hyopneumoniae and UEA-I was especially prominent in the luminal surface of bronchial and bronchiolar epithelial cells in serial section of lung. The mean number of M. hyopneumoniae-positive cells correlated with the mean number of UEA-I-positive cells in lungs from infected pigs throughout the experiment. All eight P. multocida type A isolates from naturally occurring enzootic pneumonia, bound strongly at levels of 2 μg and 5 μg of L-fucose. CONCLUSIONS: The results of the present study demonstrate that M. hyopneumoniae increases the L-fucose composition to enhance adherence of P. multocida type A to the bronchial and bronchiolar epithelial cells

Effect of intracoronary adenosine on ergonovine-induced vasoconstricted coronary arteries

Background: This study aimed to evaluate the effect of adenosine on epicardial coronary artery diameterduring ergonovine provocation testing.Methods: A total of 158 patients who underwent an ergonovine provocation test with intracoronaryadenosine injection between 2011 and 2014 were selected. Patients were divided into four groups basedon the severity of percent diameter stenosis following intracoronary ergonovine administration: Group 1,induced spasm < 50%; Group 2, 50–89%; Group 3, 90–99%; and Group 4, total occlusion.Results: Spasm positivity was observed in 44 (27.8%) cases in the study population (mean age, 57.4 ±± 10.7 years). Intracoronary adenosine increased the diameter of the ergonovine-induced epicardialartery by 0.51 ± 0.31 mm, 0.73 ± 0.39 mm, 0.44 ± 0.59 mm, and 0.01 ± 0.04 mm in Groups 1, 2, 3,and 4, respectively. Subsequent administration of nitroglycerin further increased vessel diameter by0.49 ± 0.28 mm, 0.93 ± 0.68 mm, 2.11 ± 1.25 mm, and 2.23 ± 0.69 mm in Groups 1, 2, 3, and 4,respectively. The ratios of adenosine-induced diameter to reference diameter were significantly lowerin patients with spasm positive results (0.68 [0.59–0.76] vs. 0.18 [0.00–0.41], p < 0.001 in the studypopulation; 0.60 [0.54–0.67] vs. 0.40 [0.27–0.44], p < 0.001 in Group 2) with the best cut-off value of0.505 (sensitivity 0.955, specificity 0.921).Conclusions: Intracoronary administration of adenosine dilated the ergonovine-induced vasoconstrictedepicardial coronary artery. The ratio of adenosine-induced diameter to reference diameter wassignificantly lower in patients with spasm positive results

IQ Collaboratory III: The Empirical Dust Attenuation Framework -- Taking Hydrodynamical Simulations with a Grain of Dust

We present the Empirical Dust Attenuation (EDA) framework -- a flexible prescription for assigning realistic dust attenuation to simulated galaxies based on their physical properties. We use the EDA to forward model synthetic observations for three state-of-the-art large-scale cosmological hydrodynamical simulations: SIMBA, IllustrisTNG, and EAGLE. We then compare the optical and UV color-magnitude relations, $(g-r) - M_r$ and $(FUV-NUV)-M_r$, of the simulations to a $M_r < -20$ and UV complete SDSS galaxy sample using likelihood-free inference. Without dust, none of the simulations match observations, as expected. With the EDA, however, we can reproduce the observed color-magnitude with all three simulations. Furthermore, the attenuation curves predicted by our dust prescription are in good agreement with the observed attenuation-slope relations and attenuation curves of star-forming galaxies. However, the EDA does not predict star-forming galaxies with low $A_V$ since simulated star-forming galaxies are intrinsically much brighter than observations. Additionally, the EDA provides, for the first time, predictions on the attenuation curves of quiescent galaxies, which are challenging to measure observationally. Simulated quiescent galaxies require shallower attenuation curves with lower amplitude than star-forming galaxies. The EDA, combined with forward modeling, provides an effective approach for shedding light on dust in galaxies and probing hydrodynamical simulations. This work also illustrates a major limitation in comparing galaxy formation models: by adjusting dust attenuation, simulations that predict significantly different galaxy populations can reproduce the same UV and optical observations.Comment: 26 pages, 15 figure

HMGB1, a potential regulator of tumor microenvironment in KSHV-infected endothelial cells

High-mobility group box 1 (HMGB1) is a protein that binds to DNA and participates in various cellular processes, including DNA repair, transcription, and inflammation. It is also associated with cancer progression and therapeutic resistance. Despite its known role in promoting tumor growth and immune evasion in the tumor microenvironment, the contribution of HMGB1 to the development of Kaposi’s sarcoma (KS) is not well understood. We investigated the effect of HMGB1 on KS pathogenesis using immortalized human endothelial cells infected with Kaposi’s sarcoma-associated human herpes virus (KSHV). Our results showed that a higher amount of HMGB1 was detected in the supernatant of KSHV-infected cells compared to that of mock-infected cells, indicating that KSHV infection induced the secretion of HMGB1 in human endothelial cells. By generating HMGB1 knockout clones from immortalized human endothelial cells using CRISPR/Cas9, we elucidated the role of HMGB1 in KSHV-infected endothelial cells. Our findings indicate that the absence of HMGB1 did not induce lytic replication in KSHV-infected cells, but the cell viability of KSHV-infected cells was decreased in both 2D and 3D cultures. Through the antibody array for cytokines and growth factors, CXCL5, PDGF-AA, G-CSF, Emmprin, IL-17A, and VEGF were found to be suppressed in HMGB1 KO KSHV-infected cells compared to the KSHV-infected wild-type control. Mechanistically, phosphorylation of p38 would be associated with transcriptional regulation of CXCL5, PDGF-A and VEGF. These observations suggest that HMGB1 may play a critical role in KS pathogenesis by regulating cytokine and growth factor secretion and emphasize its potential as a therapeutic target for KS by modulating the tumor microenvironment