380 research outputs found

    Effect of Crystallization Modes in TIPS-Pentacene/Insulating Polymer Blends on the Gas Sensing Properties of Organic Field-Effect Transistors

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    Blending organic semiconductors with insulating polymers has been known to be an effective way to overcome the disadvantages of single-component organic semiconductors for high-performance organic field-effect transistors (OFETs). We show that when a solution processable organic semiconductor (6,13-bis(triisopropylsilylethynyl)pentacene, TIPS-pentacene) is blended with an insulating polymer (PS), morphological and structural characteristics of the blend films could be significantly influenced by the processing conditions like the spin coating time. Although vertical phase-separated structures (TIPS-pentacene-top/PS-bottom) were formed on the substrate regardless of the spin coating time, the spin time governed the growth mode of the TIPS-pentacene molecules that phase-separated and crystallized on the insulating polymer. Excess residual solvent in samples spun for a short duration induces a convective flow in the drying droplet, thereby leading to one-dimensional (1D) growth mode of TIPS-pentacene crystals. In contrast, after an appropriate spin-coating time, an optimum amount of the residual solvent in the film led to two-dimensional (2D) growth mode of TIPS-pentacene crystals. The 2D spherulites of TIPS-pentacene are extremely advantageous for improving the field-effect mobility of FETs compared to needle-like 1D structures, because of the high surface coverage of crystals with a unique continuous film structure. In addition, the porous structure observed in the 2D crystalline film allows gas molecules to easily penetrate into the channel region, thereby improving the gas sensing properties

    In vitro ability of Staphylococcus aureus isolates from bacteraemic patients with and without metastatic complications to invade vascular endothelial cells

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    Invasion of vascular endothelial cells is thought to be a critical step in the development of metastatic infections in patients with Staphylococcus aureus bacteraemia. This study was designed to evaluate the association between the ability to invade endothelial cells and metastatic infection by S. aureus. Patients with metastatic infection were identified among those with community-acquired S. aureus bacteraemia in a tertiary referral hospital. Patients with simple bacteraemia caused by S. aureus over the same period served as the control group. The ability of each clinical isolate to invade endothelial cells was evaluated by counting the number of intracellular organisms 1 h after inoculation onto human umbilical vein endothelial cells in vitro. The cytotoxic activity of intracellular S. aureus was determined 24 h after internalization, and expressed as the percentage of cells killed. The clinical isolates varied in invasiveness and cytotoxicity. The median invasiveness, relative to S. aureus reference strain ATCC 29213, was 145 % in the cases (n=10) [interquartile range (IQR) 103-160] and 153 % (IQR 111-173) in the controls (n=11; P=0.44). The median cytotoxicity was 59.4 % (IQR 47-68) in the cases and 65.2 % (IQR 50-74) in the controls (P=0.44). Differences in the ability of S. aureus to invade and destroy vascular endothelial cells in vitro were not associated with the development of metastatic complications in patients with S. aureus bacteraemia. This implies that the invasiveness and toxicity of S. aureus for endothelial cells may not be major determinants of metastatic infection.The work was supported by grant no. 02-05-026 from the research fund of Seoul National University Bundang Hospital

    First snapshot on behavioral characteristics and related factors of patients with chronic kidney disease in South Korea during the COVID-19 pandemic (June to October 2020)

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    Background The recent novel coronavirus disease 2019 (COVID-19) pandemic has led to unprecedented changes in behavior. We evaluated the current status of precautionary behavior and physical activity in chronic kidney disease (CKD) patients during the COVID-19 pandemic. Methods A population of CKD patients (n = 306) registered in the Study on Kidney Disease and Environmental Chemicals (SKETCH, Clinical Trial No. NCT04679168) cohort recruited from June 2020 to October 2020 was included in the study. We conducted a questionnaire survey related to risk perception of COVID-19, precautionary behavior, and physical activity. Results There were 187 patients (61.1%) with estimated glomerular filtration rate of <45 mL/min/1.73 m2. This population showed a higher degree of risk perception for COVID-19 than the general population. Age was the most significant determinant of risk perception among CKD patients. During the pandemic, social distancing and hygiene-related behavior were significantly increased (p < 0.001). The frequency of exercise was decreased only in those who took regular exercise, without diabetes, or with a lower Charlson comorbidity index (CCI) (p < 0.001), with no change among the other groups. Socioeconomic status and comorbidities significantly affected behavioral characteristics regardless of the category. Education and income were significantly associated with precautionary behaviors such as staying at home and hand sanitizer use. Patients with higher CCI status significantly increased frequency of exercise (adjusted odds ratio, 2.10; 95% confidence interval, 1.01–4.38). Conclusion CKD patients showed higher risk perception with active precautionary behavioral changes than the general population. Healthcare providers should be aware of the characteristics to comprise precautionary behavior without reducing physical activity

    Post-transcriptional Regulation of NK Cell Activation

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    Natural killer (NK) cells play key roles in innate and adaptive immune defenses. NK cell responses are mediated by two major mechanisms: the direct cytolysis of target cells, and immune regulation by production of various cytokines. Many previous reports show that the complex NK cell activation process requires de novo gene expression regulated at both transcriptional and post-transcriptional levels. Specialized un-translated regions (UTR) of mRNAs are the main mechanisms of post-transcriptional regulation. Analysis of post-transcriptional regulation is needed to clearly understand NK cell biology and, furthermore, harness the power of NK cells for therapeutic aims. This review summarizes the current understanding of mRNA metabolism during NK cell activation, focusing primarily on post-transcriptional regulation

    Hemo-metabolic impairment in patients with ST-segment elevation myocardial infarction: Data from the INTERSTELLAR registry

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    Background: Not only hemo-dynamic (HD) factors but also hemo-metabolic (HM) risk factors reflecting multi-organ injuries are considered as important prognostic factors in ST-segment elevation myocardial infarction (STEMI). However, studies regarding HM risk factors in STEMI patients are currently limited. Method: Under analysis were 1,524 patients with STEMI who underwent primary percutaneous coronary intervention in the INTERSTELLAR registry. Patients were divided into HM (≥ 2 risk factors) and non-HM impairment groups. The primary outcome was in-hospital all-cause mortality, and the secondary outcome was 1-year all-cause mortality. Results: Of 1,524 patients, 214 (14.0%) and 1,310 (86.0%) patients were in the HM and non-HM impairment groups, respectively. Patients with HM impairment had a higher incidence of in-hospital mortality than those without (24.3% vs. 2.7%, p &lt; 0.001). After adjusting for confounders, HM impairment was independently associated with in-hospital mortality (inverse probability of treatment weighting [IPTW]-adjusted odds ratio: 1.81, 95% confidence interval: 1.08–3.14). In the third door-to-balloon (DTB) time tertile (≥ 82 min), HM impairment was strongly associated with in-hospital mortality. In the first DTB time tertile ( &lt; 62 min), indicating relatively rapid revascularization, HM impairment was consistently associated with increased in-hospital mortality. Conclusions: Hemo-metabolic impairment is significantly associated with increased risk of in-hospital and 1-year mortality in patients with STEMI. It remains a significant prognostic factor, regardless of DTB time

    Effect of shared decision-making education on physicians’ perceptions and practices of end-of-life care in Korea

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    Background Evidence of the ethical appropriateness and clinical benefits of shared decision-making (SDM) are accumulating. This study aimed to not only identify physicians’ perspectives on SDM, and practices related to end-of-life care in particular, but also to gauge the effect of SDM education on physicians in Korea. Methods A 14-item questionnaire survey using a modified Delphi process was delivered to nephrologists and internal medicine trainees at 17 university hospitals. Results A total of 309 physicians completed the survey. Although respondents reported that 69.9% of their practical decisions were made using SDM, 59.9% reported that it is not being applied appropriately. Only 12.3% of respondents had received education on SDM as part of their training. The main obstacles to appropriate SDM were identified as lack of time (46.0%), educational materials and tools (29.4%), and education on SDM (24.3%). Although only a few respondents had received training on SDM, the proportion of those who thought they were using SDM appropriately in actual practice was high; the proportion of those who chose lack of time and education as factors that hindered the proper application of SDM was low. Conclusion The majority of respondents believed that SDM was not being implemented properly in Korea, despite its use in actual practice. To improve the effectiveness of SDM in the Korean medical system, appropriate training programs and supplemental policies that guarantee sufficient application time are required

    Penilaian Kinerja Keuangan Koperasi di Kabupaten Pelalawan

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    This paper describe development and financial performance of cooperative in District Pelalawan among 2007 - 2008. Studies on primary and secondary cooperative in 12 sub-districts. Method in this stady use performance measuring of productivity, efficiency, growth, liquidity, and solvability of cooperative. Productivity of cooperative in Pelalawan was highly but efficiency still low. Profit and income were highly, even liquidity of cooperative very high, and solvability was good

    Juxtaposing BTE and ATE – on the role of the European insurance industry in funding civil litigation

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    One of the ways in which legal services are financed, and indeed shaped, is through private insurance arrangement. Two contrasting types of legal expenses insurance contracts (LEI) seem to dominate in Europe: before the event (BTE) and after the event (ATE) legal expenses insurance. Notwithstanding institutional differences between different legal systems, BTE and ATE insurance arrangements may be instrumental if government policy is geared towards strengthening a market-oriented system of financing access to justice for individuals and business. At the same time, emphasizing the role of a private industry as a keeper of the gates to justice raises issues of accountability and transparency, not readily reconcilable with demands of competition. Moreover, multiple actors (clients, lawyers, courts, insurers) are involved, causing behavioural dynamics which are not easily predicted or influenced. Against this background, this paper looks into BTE and ATE arrangements by analysing the particularities of BTE and ATE arrangements currently available in some European jurisdictions and by painting a picture of their respective markets and legal contexts. This allows for some reflection on the performance of BTE and ATE providers as both financiers and keepers. Two issues emerge from the analysis that are worthy of some further reflection. Firstly, there is the problematic long-term sustainability of some ATE products. Secondly, the challenges faced by policymakers that would like to nudge consumers into voluntarily taking out BTE LEI

    Search for stop and higgsino production using diphoton Higgs boson decays

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    Results are presented of a search for a "natural" supersymmetry scenario with gauge mediated symmetry breaking. It is assumed that only the supersymmetric partners of the top-quark (stop) and the Higgs boson (higgsino) are accessible. Events are examined in which there are two photons forming a Higgs boson candidate, and at least two b-quark jets. In 19.7 inverse femtobarns of proton-proton collision data at sqrt(s) = 8 TeV, recorded in the CMS experiment, no evidence of a signal is found and lower limits at the 95% confidence level are set, excluding the stop mass below 360 to 410 GeV, depending on the higgsino mass

    Severe early onset preeclampsia: short and long term clinical, psychosocial and biochemical aspects

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    Preeclampsia is a pregnancy specific disorder commonly defined as de novo hypertension and proteinuria after 20 weeks gestational age. It occurs in approximately 3-5% of pregnancies and it is still a major cause of both foetal and maternal morbidity and mortality worldwide1. As extensive research has not yet elucidated the aetiology of preeclampsia, there are no rational preventive or therapeutic interventions available. The only rational treatment is delivery, which benefits the mother but is not in the interest of the foetus, if remote from term. Early onset preeclampsia (<32 weeks’ gestational age) occurs in less than 1% of pregnancies. It is, however often associated with maternal morbidity as the risk of progression to severe maternal disease is inversely related with gestational age at onset2. Resulting prematurity is therefore the main cause of neonatal mortality and morbidity in patients with severe preeclampsia3. Although the discussion is ongoing, perinatal survival is suggested to be increased in patients with preterm preeclampsia by expectant, non-interventional management. This temporising treatment option to lengthen pregnancy includes the use of antihypertensive medication to control hypertension, magnesium sulphate to prevent eclampsia and corticosteroids to enhance foetal lung maturity4. With optimal maternal haemodynamic status and reassuring foetal condition this results on average in an extension of 2 weeks. Prolongation of these pregnancies is a great challenge for clinicians to balance between potential maternal risks on one the eve hand and possible foetal benefits on the other. Clinical controversies regarding prolongation of preterm preeclamptic pregnancies still exist – also taking into account that preeclampsia is the leading cause of maternal mortality in the Netherlands5 - a debate which is even more pronounced in very preterm pregnancies with questionable foetal viability6-9. Do maternal risks of prolongation of these very early pregnancies outweigh the chances of neonatal survival? Counselling of women with very early onset preeclampsia not only comprises of knowledge of the outcome of those particular pregnancies, but also knowledge of outcomes of future pregnancies of these women is of major clinical importance. This thesis opens with a review of the literature on identifiable risk factors of preeclampsia
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