1,301 research outputs found
(7-Dimethylamino-1-hydroxy-3-naphthyl)(morpholino)methanone
In the title compound, C17H20N2O3, the morpholine ring is in a slightly distorted chair form. The crystal structure is stabilized by an intermolecular O—H⋯O hydrogen bond between the H atom of the hydroxyl group and the O atom of a neighbouring carbonyl group. A weak intermolecular C—H⋯π interaction is also present
Chirality of a resonance in the absence of backscatterings
Chirality of a resonance localized on an islands chain is studied in a deformed Reuleaux triangular-shaped microcavity, where clockwise and counter clockwise traveling rays are classically separated. A resonance localized on a period-5 islands chain exhibits chiral emission due to the asymmetric cavity shape. Chirality is experimentally proved in a InGaAsP multiquantum-well semiconductor laser by showing that the experimental emission characteristics well coincide with the wave dynamical ones. (C) 2017 Optical Society of America1
COMPARISON OF THE EFFECT OF TMP PITCH CONTROL AGENTS WITH DIFFERENT MECHANISMS
The pitch contained in thermomechanical pulp negatively affects paper quality, pulp, and the papermaking process. Serious pitch and stickies problems may occur in paper recycling processes. In this study, the effects of chemicals used to control the pitch in the TMP(Themomechanical Pulp) rocess were compared. The method used to analyze the pitch-control effect was to perform image analysis after using a reagent that selectively stains only the hydrophobic pitch. Three different mechanisms, namely fixation, detackification, and dispersion, were applied to solve the pitch problem from TMP. All the control agents were effective in pitch control, and, in particular, the agents related to fixation and dispersion were found to be more effective in reducing the number and area of tacky particles per unit area in sheets and white water. However, for the detackifiers and the dispersants, but not for the fixatives, it was difficult to clearly distinguish the difference of the pitch control effects according to the change in the amount of these agents through image analysis after staining
Comparing the cut score for the borderline group method and borderline regression method with norm-referenced standard setting in an objective structured clinical examination in medical school in Korea
Purpose Setting standards is critical in health professions. However, appropriate standard setting methods do not always apply to the set cut score in performance assessment. The aim of this study was to compare the cut score when the standard setting is changed from the norm-referenced method to the borderline group method (BGM) and borderline regression method (BRM) in an objective structured clinical examination (OSCE) in medical school. Methods This was an explorative study to model the implementation of the BGM and BRM. A total of 107 fourth-year medical students attended the OSCE at 7 stations for encountering standardized patients (SPs) and at 1 station for performing skills on a manikin on July 15th, 2021. Thirty-two physician examiners evaluated the performance by completing a checklist and global rating scales. Results The cut score of the norm-referenced method was lower than that of the BGM (P<0.01) and BRM (P<0.02). There was no significant difference in the cut score between the BGM and BRM (P=0.40). The station with the highest standard deviation and the highest proportion of the borderline group showed the largest cut score difference in standard setting methods. Conclusion Prefixed cut scores by the norm-referenced method without considering station contents or examinee performance can vary due to station difficulty and content, affecting the appropriateness of standard setting decisions. If there is an adequate consensus on the criteria for the borderline group, standard setting with the BRM could be applied as a practical and defensible method to determine the cut score for OSCE
A new cognition-based chat system for avatar agents in virtual space
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Effect of Hydraulic Activity on Crystallization of Precipitated Calcium Carbonate (PCC) for Eco-Friendly Paper
Wt% of aragonite, a CaCO3 polymorph, increased with higher hydraulic activity (°C) of limestone in precipitated calcium carbonate (PCC) from the lime-soda process (Ca(OH)2-NaOH-Na2CO3). Only calcite, the most stable polymorph, was crystallized at hydraulic activity under 10 °C, whereas aragonite also started to crystallize over 10 °C. The crystallization of PCC is more dependent on the hydraulic activity of limestone than CaO content, a factor commonly used to classify limestone ores according to quality. The results could be effectively applied to the determination of polymorphs in synthetic PCC for eco-friendly paper manufacture
Bacterial Uracil Modulates Drosophila DUOX-Dependent Gut Immunity via Hedgehog-Induced Signaling Endosomes
SummaryGenetic studies in Drosophila have demonstrated that generation of microbicidal reactive oxygen species (ROS) through the NADPH dual oxidase (DUOX) is a first line of defense in the gut epithelia. Bacterial uracil acts as DUOX-activating ligand through poorly understood mechanisms. Here, we show that the Hedgehog (Hh) signaling pathway modulates uracil-induced DUOX activation. Uracil-induced Hh signaling is required for intestinal expression of the calcium-dependent cell adhesion molecule Cadherin 99C (Cad99C) and subsequent Cad99C-dependent formation of endosomes. These endosomes play essential roles in uracil-induced ROS production by acting as signaling platforms for PLCβ/PKC/Ca2+-dependent DUOX activation. Animals with impaired Hh signaling exhibit abolished Cad99C-dependent endosome formation and reduced DUOX activity, resulting in high mortality during enteric infection. Importantly, endosome formation, DUOX activation, and normal host survival are restored by genetic reintroduction of Cad99C into enterocytes, demonstrating the important role for Hh signaling in host resistance to enteric infection
Unidirectional emission of high-Q scarred modes in a rounded D-shape microcavity
We propose a deformed microcavity laser, where a high-Q mode group emits unidirectionally. The cavity comprises three circular arcs and one linear section. To minimize diffraction effects from the boundary, three circular arcs and one linear section are tangentially connected. By adjusting the sizes and the positions of the two sub-circular arcs, unidirectionality is maximized. In an experiment with an InP based InGaAsP semiconductor microcavity laser, a lasing mode group localized on a period-7 unstable periodic orbit emits unidirectionally. In our resonance calculation, a high-Q factor is confirmed. © 2018 Optical Society of America under the terms of the OSA Open Access Publishing Agreement1
Enhancement of seawater corrosion resistance in copper using acetone-derived graphene coating
We show that acetone-derived graphene coating can effectively enhance the corrosion efficiency of copper (Cu) in a seawater environment (0.5-0.6 M (???3.0-3.5%) sodium chloride). By applying a drop of acetone (???20 ??l cm-2) on Cu surfaces, rapid thermal annealing allows the facile and rapid synthesis of graphene films on Cu surfaces with a monolayer coverage of almost close to ???100%. Under optimal growth conditions, acetone-derived graphene is found to have a relatively high crystallinity, comparable to common graphene grown by chemical vapor deposition. The resulting graphene-coated Cu surface exhibits 37.5 times higher corrosion resistance as compared to that of mechanically polished Cu. Further, investigation on the role of graphene coating on Cu surfaces suggests that the outstanding corrosion inhibition efficiency (IE) of 97.4% is obtained by protecting the underlying Cu against the penetration of both dissolved oxygen and chlorine ions, thanks to the closely spaced atomic structure of the graphene sheets. The increase of graphene coating thickness results in the enhancement of the overall corrosion IE up to ???99%, which can be attributed to the effective blocking of the ionic diffusion process via grain boundaries. Overall, our results suggest that the acetone-derived graphene film can effectively serve as a corrosion-inhibiting coating in the seawater level and that it may have a promising role to play for potential offshore coating.close0
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