Nanocomposites consisting of styrene butadiene rubber (SBR) reinforced with the modified-graphite and natural-graphite with concentrations of 5
wt% were fabricated. Processing techniques such as acid ...treatment, thermal shock, sonication were employed in the fabrication of modified-graphite.
The graphite platelets oxidized using sulfuric and nitric acids were analyzed by the Raman scattering, Fourier transformed infrared spectroscopy (FT-IR) and X-ray diffraction (XRD). The FT-IR results indicate the presence of acid groups in the treated samples, and Raman spectroscopy of acid-graphite platelets further corroborate the formation of surface defect due to the introduction of functional groups. However, the structure of XRD peaks did not change irrespective of processing techniques.
The SBR-based nanocomposites were characterized using the scanning electron microscopy (SEM), rheometer, Instron tensile machine, thermal and electrical analyser.
The results showed that nanocomposites onto acid-graphite platelets enhanced mechanical properties and fatigue properties of nanocomposites compared to those containing natural-graphite due to the increase in the interaction between the polymer and the modified-graphite. And the dynamic properties of nanocomposites had no influence according to the processing techniques. Also, thermal and electrical properties of nanocomposites using acid-graphite platelets were enhanced due to the broadened specific surface by the acid treatment.
Acute exacerbation of COPD (AECOPD) leads to rapid deterioration of pulmonary function and quality of life. It is unclear whether the prognosis for AECOPD differs depending on the bacterium or virus ...identified. The purpose of this study is to determine whether readmission of patients with severe AECOPD varies according to the bacterium or virus identified.
We performed a retrospective review of medical records of 704 severe AECOPD events at Korea University Guro Hospital from January 2011 to May 2017. We divided events into two groups, one in which patients were readmitted within 30 days after discharge and the other in which there was no readmission.
Of the 704 events, 65 were followed by readmission within 30 days. Before propensity score matching, the readmission group showed a higher rate of bacterial identification with no viral identification and a higher rate of identification with the
(
=0.003 and
=0.007, respectively). Using propensity score matching, the readmission group still showed a higher
identification rate (
=0.030), but there was no significant difference in the rate of bacterial identification, with no viral identification (
=0.210). In multivariate analysis, the readmission group showed a higher
identification rate than the no-readmission group (odds ratio, 4.749; 95% confidence interval, 1.296-17.041;
=0.019).
identification is associated with a higher readmission rate in AECOPD patients.
Summary
We evaluated the clinical usefulness (leukocyte distribution classification, morphologic classification, and morphologic flags) of the following four hematology analyzers: CELL‐DYN Sapphire ...(CD‐Sapphire) (Abbott Diagnostics, Santa Clara, CA, USA), ADVIA 120 (Bayer Diagnostics, Tarrytown, NY, USA), Beckman Coulter LH 750 (Beckman Coulter, Miami, FL, USA), and Sysmex XE‐2100 (TOA Medical Electronics Co., Kobe, Japan). Four hundred thirty samples from patients and 100 samples from healthy individuals were analyzed. For distributional classification, the sensitivity rates of CD‐Sapphire, ADVIA 120, LH 750, and XE‐2100 were 93.1, 95.9, 94.9, and 94.9%, respectively, and the efficiency rates were 80.7, 81.6, 84.1, and 84.2%, respectively. For morphologic classification, the sensitivity rates of CD‐Sapphire, ADVIA 120, LH 750, and XE‐2100 were 88.6, 93.2, 77.3, and 94.3%, respectively, and the efficiency rates were 80.9, 73.0, 79.5, and 74.2%, respectively. Comparing the findings in different morphologic flags, XE‐2100 showed the highest sensitivity for Blasts flag (90.9%); CD‐Sapphire showed the highest sensitivity for Immature granulocytes and/or Left‐shift flag (85.5%); ADVIA 120 showed the highest sensitivity for Atypical lymphocytes flag (60.0%); and LH 750 showed the highest sensitivity for Nucleated RBC flag (75.0%). Our results demonstrate that the four analyzers are comparable in overall performance.
Although transforming growth factor-β (TGF-β) has been identified to mainly inhibit cell growth, the correlation of elevated TGF-β with increasing serum prostate-specific antigen (PSA) levels in ...metastatic stages of prostate cancer has also been well documented. The molecular mechanism for these two contrasting effects of TGF-β, however, remains unclear. Here we report that Smad3, a downstream mediator of the TGF-β signaling pathway, functions as a coregulator to enhance androgen receptor (AR)-mediated transactivation. Compared with the wild-type AR, Smad3 acts as a strong coregulator in the presence of 1 nM 5α-dihydrotestosterone, 10 nM 17 β-estradiol, or 1 µM hydroxyflutamide for the LNCaP mutant AR (mtAR T877A), found in many prostate tumor patients. We further showed that endogenous PSA expression in LNCaP cells can be induced by 5α-dihydrotestosterone, and the addition of the Smad3 further induces PSA expression. Together, our findings establish Smad3 as an important coregulator for the androgen-signaling pathway and provide a possible explanation for the positive role of TGF-β in androgen-promoted prostate cancer growth.
Objectives Methicillin-resistant Staphylococcus aureus (MRSA), originally restricted to hospitals, has emerged as a significant pathogen in the community. Although MRSA accounts for over 60% of S. ...aureus in tertiary hospitals in Korea, little is known about the epidemiology of community-associated MRSA (CA-MRSA). Methods From January to July 2005, a hospital laboratory-based survey was conducted in seven community-based or tertiary hospitals. The medical records and Health Insurance Review Agency databases were reviewed and MRSA isolated from patients without apparent risk factors was defined as CA-MRSA. Susceptibilities to 12 antibiotics were tested by the disc diffusion method. SCCmec typing, Panton–Valentine leucocidin (PVL) gene detection and multilocus sequence typing (MLST) were performed according to published protocols. Results Of 3251 S. aureus, 1900 (58.4%) were MRSA. CA-MRSA accounted for 112 (5.9%) of the MRSA. Of the 112 CA-MRSA isolates, 27 and 33 were found to be pathogens and colonizers, respectively. Fifty-two isolates from the patients with chronic otitis media were classified as ‘undetermined’. Most of the 27 CA-MRSA patients had skin and soft tissue infections or acute ear infections. None of the patients died during the study period. Among 72 isolates tested, 64% were multidrug-resistant. SCCmec type IVa was the most common type among the colonizers and pathogens. On MLST analysis, ST72 was predominant, but ST5 and ST239 were prevalent in the ‘undetermined’ group. None possessed the PVL gene. Conclusions Despite MRSA-endemic hospital settings, CA-MRSA infections are not common in Korea. A new clone of CA-MRSA, ST72-SCCmec type IVa without the PVL gene, is the most common form.
An experimental investigation was carried out to measure module average heat transfer coefficients in uniformly heated rectangular channel with wall mounted porous baffles. Baffles were mounted ...alternatively on top and bottom of the walls. Heat transfer coefficients and pressure loss for periodically fully developed flow and heat transfer were obtained for different types of porous medium (10, 20, and 40 pores per inch (PPI)) with two window cut ratios (
B
h/
D
h=1/3 and 2/3) and two baffle thickness to channel hydraulic diameter ratios (
B
t/
D
h=1/3 and 1/12). Reynolds number (
Re) was varied from 20,000 to 50,000. To compare the effect of foam metal baffle, the data for conventional solid-type baffle were obtained for (
B
t/
D
h=1/3). The maximum uncertainties associated with module Nusselt number and friction factor were 5.8% and 4.3% respectively. The experimental procedure was validated by comparing the data for the straight channel with no baffles (
B
h/
D
h=0) with those in the literature Publications in Engineering, vol. 2, University of California, Berkeley, 1930, p. 443; Int. Chem. Eng. 16 (1976) 359. The use of porous baffles resulted in heat transfer enhancement as high as 300% compared to heat transfer in straight channel with no baffles. However, the heat transfer enhancement per unit increase in pumping power was less than one for the range of parameters studied in this work. Correlation equations were developed for heat transfer enhancement ratio and heat transfer enhancement per unit increase in pumping power in terms of Reynolds number.
Prostaglandin (PGE2), synthesized by cyclooxygenase-2 (COX-2), is associated with cellular immune tolerance during the process of cancer development. Induction of tolerance requires a specific ...environment in which dendritic cells and regulatory T cells (Tregs) play an essential role. It was recently shown that maturation of dendritic cells in the presence of indoleamine 2, 3-dioxygenase (IDO) results in activation of Tregs, and inhibition of COX-2 activity regulated IDO expression within the tumor microenvironment. Thus, we hypothesized that the tumor immune tolerance would be inhibited by COX-2 inhibitor and this inhibition would be mediated by IDO-dependent Tregs inhibition. The PGE2 in Lewis lung cancer cells (3LL) and serum of mice were measured for the evaluation of COX-2 inhibitors' local and systemic effects. The production of PGE2 in 3LL cells and serum of 3LL tumor-bearing mice were decreased by COX-2 inhibition. However, there were no significant differences in serum PGE2 levels among normal control and celecoxib-treated nontumor-bearing mice. The accumulation of Tregs was reduced in the celecoxib-treated 3LL tumor-bearing mice. In addition, the expressions of COX-2, IDO, and Foxp3 were reduced in the mice treated with a COX-2 inhibitor, and this was found to correlate with a reduction in the size of tumor mass and metastasis. These results suggest that the antitumor effects of COX-2 inhibitors seemed to be correlated with the inhibition of IDO and Tregs. Therefore, COX-2 inhibitors might provide a therapeutic strategy for Tregs-induced tumor immune tolerance.
Motivation is fundamental to human agency and volitional behavior, and several influential theories have been proposed to explain why individuals choose or persist in a course of action (over ...others). New terms and concepts have proliferated as the theoretical models aim to be comprehensive, at the expense of parsimony. The theoretical models covered in this special issue each have their unique aspects and contributions, but four major dimensions cut across them: person factors comprising self (expectations, self-efficacy), social (modeling, comparisons), and cognitive aspects (self-regulation); task values; goals; and perceived costs and benefits. Motivation is determined by a complex interplay of internal and external factors, and we suggest that a greater focus on individuals’ motivation profiles, construal of situations, and metacognitive monitoring and control of goal pursuit might shed more light on the moment-by-moment decisions people make in daily life. Future research could be targeted at evaluating competing models (or perhaps more parsimonious ones) and enhancing interventions to address students who are unmotivated to excel in school.
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