OBJECTIVETo determine whether quantitative EEG (QEEG) features predict neurologic outcomes in children after cardiac arrest.
METHODSWe performed a single-center prospective observational study of 87 ...consecutive children resuscitated and admitted to the pediatric intensive care unit after cardiac arrest. Full-array conventional EEG data were obtained as part of clinical management. We computed 8 QEEG features from 5-minute epochs every hour after return of circulation. We developed predictive models utilizing random forest classifiers trained on patient age and 8 QEEG features to predict outcome. The features included SD of each EEG channel, normalized band power in alpha, beta, theta, delta, and gamma wave frequencies, line length, and regularity function scores. We measured outcomes using Pediatric Cerebral Performance Category (PCPC) scores. We evaluated the models using 5-fold cross-validation and 1,000 bootstrap samples.
RESULTSThe best performing model had a 5-fold cross-validation accuracy of 0.8 (0.88 area under the receiver operating characteristic curve). It had a positive predictive value of 0.79 and a sensitivity of 0.84 in predicting patients with favorable outcomes (PCPC score of 1–3). It had a negative predictive value of 0.8 and a specificity of 0.75 in predicting patients with unfavorable outcomes (PCPC score of 4–6). The model also identified the relative importance of each feature. Analyses using only frontal electrodes did not differ in prediction performance compared to analyses using all electrodes.
CONCLUSIONSQEEG features can standardize EEG interpretation and predict neurologic outcomes in children after cardiac arrest.
Enhancer RNAs (eRNAs) are non-coding RNAs produced by transcriptional enhancers that are highly correlated with their activity. Using a capped nascent RNA sequencing (PRO-cap) dataset in human ...lymphoblastoid cell lines across 67 individuals, we identified inter-individual variation in the expression of over 80 thousand transcribed transcriptional regulatory elements (tTREs), in both enhancers and promoters. Co-expression analysis of eRNAs from tTREs across individuals revealed how enhancers are associated with each other and with promoters. Mid- to long-range co-expression showed a distance-dependent decay that was modified by TF occupancy. In particular, we found a class of "bivalent" TFs, including Cohesin, that both facilitate and isolate the interaction between enhancers and/or promoters, depending on their topology. At short distances, we observed strand-specific correlations between nearby eRNAs in both convergent and divergent orientations. Our results support a cooperative model of convergent eRNAs, consistent with eRNAs facilitating adjacent enhancers rather than interfering with each other. Therefore, our approach to infer functional interactions from co-expression analyses provided novel insights into the principles of enhancer interactions as a function of distance, orientation, and binding landscapes of TFs.
HY-80 and HY-100 steels, widely used in constructing large ocean vessels and submarine hulls, contain mixed microstructures of tempered bainite and martensite and provide high tensile strength and ...toughness. Weld integrity in HY steels has been studied to verify and optimize welding conditions. In this study, the T-joint weld coupons, HY80 and HY100, were fabricated from HY-80 and HY-100 steel plates with a thickness of 30 mm as base metals by submerged-arc welding. Flux-cored arc welding was performed on an additional welding coupon consisting of HY-100 to evaluate the effect of repair welds (HY100RP). Microstructures in the heat-affected zones (HAZ) were thoroughly analyzed by optical observation. Instrumented indentation testing, taking advantage of local characterization, was applied to assess the yield strength and the residual stress of the HAZ and base regions. The maximum hardness over 400 HV was found in the HAZ due to the high volume fraction of untempered martensite microstructure. The yield strength of the weld coupons was evaluated by indentation testing, and the results showed good agreement with the uniaxial tensile test (within 10% range). The three coupons showed similar indentation residual stress profiles on the top and bottom surfaces. The stress distribution of the HY100 coupon was comparable to the results from X-ray diffraction. HY100RP demonstrated increased tensile residual stress compared to the as-welded coupon due to the effect of the repair weld (323 and 103 MPa on the top and bottom surfaces). This study verifies the wide applicability of indentation testing in evaluating yield strength and residual stress.
This study describes the development of a semi-physical, real-time nitric oxide (NO) prediction model that is capable of cycle-by-cycle prediction in a light-duty diesel engine. The model utilizes ...the measured in-cylinder pressure and information obtained from the engine control unit (ECU). From the inputs, the model takes into account the pilot injection burning and mixing, which affects the in-cylinder mixture formation. The representative in-cylinder temperature for NO formation was determined from the mixture composition calculation. The selected temperature and mixture composition was substituted using a simplified form of the NO formation rate equation for the cycle-by-cycle estimation. The reactive area and the duration of NO formation were assumed to be limited by the fuel quantity. The model predictability was verified not only using various steady-state conditions, including the variation of the EGR rate, the boost pressure, the rail pressure, and the injection timing, but also using transient conditions, which represent the worldwide harmonized light vehicles test procedure (WLTC). The WLTC NO prediction results produced less than 3% error with the measured value. In addition, the proposed model maintained its reliability in terms of hardware aging, the changing and artificial perturbations during steady-state and transient engine operations. The model has been shown to require low computational effort because of the cycle-by-cycle, engine-out NO emission prediction and control were performed simultaneously in an embedded system for the automotive application. We expect that the developed NO prediction model can be helpful in emission calibration during the engine design stage or in the real-time controlling of the exhaust NO emission for improving fuel consumption while satisfying NO emission legislation.
The multiple injection strategy has been widely used in diesel engines to reduce engine noise, NOx and soot formation. Fuel injection developments such as the common-rail and piezo-actuator system ...provide more precise control of the injection quantity and time under higher injection pressures. As various injection strategies become accessible, it is important to understand the interaction of each fuel stream and following combustion process under the multiple injection strategy. To investigate these complex processes quantitatively, numerical analysis using CFD is a good alternative to overcome the limitation of experiments. A modified 2-D flamelet model is further developed from previous work to model multi-fuel streams with higher accuracy. The model was validated under various engine operating conditions and captures the combustion and emissions characteristics as well as several parametric variations. The model is expected to be used to suggest advanced injection strategies in engine development processes.
Friction stir welding has the advantages of producing less material deformation and of simple joining of relatively thick materials, but the disadvantages of forming relatively large heat-affected ...zones around weld areas. In addition, in research on reductions in bulletproof performance in heat-affected zones, it is necessary to evaluate the ballistic limit velocity (
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50
), which measures bulletproof performance, and this requires specimens of a certain minimum size and has only limited application to local areas such as heat-affected zones. Instrumented indentation testing (IIT), a method of measuring material properties by utilizing load-depth curves measured by a small indenter leaving fine marks on the material, has no specimen size requirements; in addition, it has simple test procedures and is nondestructive. Here a theoretical model is proposed for evaluating
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50
of aluminum alloys by ductile hole formation using IIT. Heat-affected zones generated after friction stir welding of for 7000-series aluminum alloys were simulated, and the model was validated through comparison with the conventional
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50
test. In addition, there is currently no way to directly evaluate
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50
for welded areas in 7000-series aluminum, but here IIT was used to assess
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for each local part of the welded specimen. The conventional
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50
test takes 15 min per shot and cannot be reused of specimens, but the test using IIT takes 1 min to complete one test and has benefits in terms of time, cost and safety.
Graphic Abstract
공간 제약 효과에 따른 전기와류 불안정성의 동역학 전이 이승하; Seungha Lee; 현철헌 ...
Korean Chemical Engineering Research(HWAHAK KONGHAK), 59(4),
11/2021, Letnik:
59, Številka:
4
Journal Article
Recenzirano
Odprti dostop
전기투석장치, 전기화학 전지, 미세유체역학 분석 장치 등에서 사용하는 이온 교환 막 근처의 대표적인 비선형 전기 동역학 현상은 전기와류 불안정성이다. 전기투석 장치에서 전기와류 불안정성은 물질 전달 속도 증폭을 통해 물질 전달에 대한 이점을 제공한다. 그러나 전기화학 전지나 미세유체역학 장치에서 발생하는 불안정성은 원치 않는 물질 전달 기작을 유발시킨다. ...본 연구에서는 전기와류 불안정성의 제어하기 위해, 인가 전압과 공간 제약 효과의 전기와류 불안정성에 대한 영향을 연구하였다. 그 결과, 인가 전압과 공간 제약의 정도에 따라 불안정성의 동역학이 안정 영역 -고정 영역 - 혼돈 영역 순으로 전이됨을 밝혀내었다. 더불어, 동역학 전이에 대한 안정성 곡선을 수치적으로 결정하였다. 결론적으로, 공간 제약 효과는 전기동역학적 혼돈을 제어할 수 있는 효과적인 기작으로 활용 가능할 것이다.
One of the nonlinear electrokinetic phenomena around ion exchange membrane is electroconvective instability which can be found in various electrokinetic applications such as electrodialysis, electrochemical battery, microfluidic analysis platform, etc. Such instability acts as a positive transport mechanism for the electrodialysis via amplifying mass transport rate. On the other hands, in the electrochemical battery and the microfluidic applications, the instability provokes unwanted mass transport. In this research, to control the electroconvective instability, the onset of the instability was analyzed as a function of confinement effect as well as applied voltage. As a result, we figured out that the dynamic behavior of electroconvective instability transited as a sequence of stable regime - static regime - chaotic regime depending on the applied voltage and confinement effect. Furthermore, stability curves about the dynamic transition were numerically determined as well. Conclusively, the confinement effect on electroconvective instability can be applied for effective means to control the electrokinetic chaos.
Evidence-based social skills interventions for young adults are limited, despite social difficulties in autism spectrum disorder (ASD) persisting after transition to adulthood. The Program for the ...Education and Enrichment of Relational Skills for Young Adults (PEERS®-YA) is an evidence-based intervention found to be effective in improving relational skills in young adults with ASD. To translate the original American version of the PEERS®-YA treatment manual into Korean, intensive interviews were performed. Based on results from interviews, several rules of dating etiquette and social activities were modified to be culturally sensitive and linguistically appropriate. Next, young adults diagnosed with ASD (18–35 years of age; IQ > 70) and their social coaches were recruited for the randomized controlled trial (RCT). Participants were randomly assigned either to a treatment group (TG;
n
= 19) or a delayed treatment group (DTG;
n
= 18). In the analysis of group differences in the TG and DTG, social skills knowledge was improved. The within group analyses showed positive effects of improving social skills knowledge on reducing depression and anxiety symptoms. After modest cultural adaptations focusing on dating and social activities, the implementation of the PEERS®-YA-K was found feasible for the Korean community. This is one of only a few cross-cultural validation trials establishing evidence-based treatment in young adults with ASD.
Clinical Trial Registration:
This trial was registered at
ClinicalTrials.gov
, identifier: NCT03310775.
Nitrosamines can be produced during the manufacture of rubber-type products such as pacifiers or the nipples of baby bottles. Humans can be exposed to the nitrosamines in these products when they are ...eluted into saliva. In this study, we compared the efficiency of electron impact ionization (EI), atmospheric pressure chemical ionization (APCI), and electrospray ionization (ESI) methods for the analysis of nine nitrosamines eluted into artificial saliva. In addition, nine nitrosamines eluted from 54 rubber-type products (rubber, thermoplastic elastomer, thermoplastic polyurethane, and polyurethane) marketed in Korea were monitored. Finally, non-carcinogenic and carcinogenic risk assessments of oral exposure to nine nitrosamines were performed based on the monitoring results. EI-GC-MS/MS performed the best for the simultaneous analysis of these nine nitrosamines with respect to overall linearity, trace analysis limit of detection (less than 1 μg), recovery (average 108.66 ± 9.32%), and precision (less than 6%), compared with liquid chromatography-tandem mass spectrometry (LC-MS/MS) (APCI and ESI) methods. Using the EI-GC-MS/MS method, these nine nitrosamines eluted into artificial saliva from 54 rubber-type products were monitored. Based on the monitoring data, risk assessment was performed by calculating the margin of exposure (MOE) for the respective nitrosamines detected. As a result, these nitrosamines were confirmed to be safe with regard to both non-carcinogenic and carcinogenic risks.
Curcumin as an anticancer agent was investigated in regards to its ability to regulate the switching of cancer cells from survival to necrotic cell death. At higher concentrations, curcumin induced ...ROS production leading to JNK and p38 phosphorylation in DU-145 prostate cancer cells. Of the MAP kinases, ERK or p38/JNK were phosphorylated earlier during curcumin treatment, and were responsible for curcumin-induced cell survival at early time of treatment with the help of phosphorylated Akt, while significant amounts of ROS production in later periods stimulated cell death with caspase degradation. In addition to autophagic signaling, necrosis was dominant with little apoptotic cell death. Caspase activation was completely prohibited by procaspase degradation, which contributed to curcumin-induced early necrosis. At the later incubation period (24h), cytotoxicity caused by curcumin peaked, at which time survival or proliferation signals, such as phosphorylated Akt and phosphorylated ERK, was almost completely diminished. Curcumin-induced ROS were shown to function, biphasically depending on the incubation period; facilitating survival, in the earlier incubation period, and necrotic death in the later. Based on all of these results, we concluded that curcumin contributes to a complex signaling network, affecting cell survival and necrotic cell death, which in turn could inhibit apoptotic cell death.
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► Curcumin mainly induces necrosis rather than apoptosis in cancer cells. ► Caspase degradation induced by curcumin occurs through autophagy-dependent. ► Necrotic cell death induced by curcumin results from complex signaling cascades.
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