Advanced CO2 Capture Process Using MEA Scrubbing: Configuration of a Split Flow and Phase Separation Heat Exchanger

AbstractCO2 capture process using aqueous Monoethanolamine (MEA) scrubbing is a well-proven and commercially-ready technology for reducing CO2 emission to the atmosphere. Although the MEA scrubbing is the one of the most suitable technologies for post-combustion CO2 capture, the MEA process has a critical problem which is high consumption of reboiler heat energy for solvent regeneration. In order to reduce the reboiler heat requirement, this paper suggests an advanced configuration of MEA process which consists of split flow and a phase separation heat exchanger. The split flow permits to reduce the reflux ratio in the stripper and the phase separation heat exchanger permits to alleviate preheating duty loss. As a result, the regeneration energy of the advanced process is reduced by 2.84GJ/ton CO2, which is lower than one of the reference process by 27%.CO2 capture; post combustion CO2 capture; advanced stripper configuration; cold solvent split; rich vapor compressio

Empirical Validation of Heat Transfer Performance Simulation of Graphite/PCM Concrete Materials for Thermally Activated Building System

To increase the heat capacity in lightweight construction materials, a phase change material (PCM) can be introduced to building elements. A thermally activated building system (TABS) with graphite/PCM concrete hollow core slab is suggested as an energy-efficient technology to shift and reduce the peak thermal load in buildings. An evaluation of heat storage and dissipation characteristics of TABS in graphite/PCM concrete has been conducted using dynamic simulations, but empirical validation is necessary to acceptably predict the thermal behavior of graphite/PCM concrete. This study aimed to validate the thermal behavior of graphite/PCM concrete through a three-dimensional transient heat transfer simulation. The simulation results were compared to experimental results from previous studies of concrete and graphite/PCM concrete. The overall thermal behavior for both materials was found to be similar to experiment results. Limitations in the simulation modeling, which included determination of the indoor heat transfer coefficient, assumption of constant thermal conductivity with temperature, and assumption of specimen homogeneity, led to slight differences between the measured and simulated results

High triglyceride/HDL cholesterol ratio is associated with silent brain infarcts in a healthy population

Background Triglycerides (TG)/high-density lipoprotein (HDL) cholesterol ratio is a marker of small/dense low-density lipoprotein particles, which are closely associated with various metabolic and vascular diseases. However, the role of TG/HDL cholesterol ratio in cerebrovascular diseases has not been well studied. In this study, we evaluated the relationship between TG/HDL cholesterol ratio and the presence of silent brain infarct (SBI) in a neurologically healthy population. Methods We retrospectively evaluated consecutive participants in health check-ups between January 2006 and December 2013. SBI was defined as an asymptomatic, well-defined lesion with a diameter of ≥3 mm on T1- or T2-weighted images. TG/HDL cholesterol ratio was calculated after dividing absolute TG levels by absolute HDL cholesterol levels. Results Of 3172 healthy participants, 263 (8.3%) had SBI lesions. In multivariate analysis, TG/HDL cholesterol ratio was independently associated with SBI (adjusted odds ratio [aOR] = 1.16, 95% confidence interval [CI] = 1.00 to 1.34, P = 0.047). This association was prominent in males (aOR = 1.23, 95% CI = 1.03 to 1.48, P = 0.021), but not in females. In the analyses of the relationships between lipid parameters and SBI lesion burden, TG/HDL cholesterol ratio was positively correlated, and total cholesterol/TG ratio was negatively correlated with SBI lesion burden, in dose-response manners (P for trend = 0.015 and 0.002, respectively). Conclusions The TG/HDL cholesterol ratio was positively associated with the prevalence of SBI in a neurologically healthy population

Effectiveness of mechanical thrombectomy in cancer-related stroke and associated factors with unfavorable outcome

Background The effectiveness of mechanical thrombectomy (MT) in cancer-related stroke (CRS) is largely unknown. This study aims to investigate the clinical and radiological outcomes of MT in CRS patients. We also explored the factors that independently affect functional outcomes of patients with CRS after MT. Methods We retrospectively reviewed 341 patients who underwent MT after acute ischemic stroke onset between May 2014 and May 2020. We classified the patients into CRS (n = 34) and control (n = 307) groups and compared their clinical details. Among CRS patients, we analyzed the groups with and without good outcomes (3-months modified Rankin scale [mRS] score 0, 1, 2). Multivariate analysis was performed to investigate the independent predictors of unfavorable outcomes in patients with CRS after MT. Results A total of 341 acute ischemic stroke patients received MT, of whom 34 (9.9%) had CRS. Although the baseline National institute of health stroke scale (NIHSS) score and the rate of successful recanalization was not significantly different between CRS patients and control group, CRS patients showed more any cerebral hemorrhage after MT (41.2% vs. controls 23.8%, p = 0.037) and unfavorable functional outcome at 3 months (CRS patients median 3-month mRS score 4, interquartile range [IQR] 2 to 5.25 vs. controls median 3-month mRS score 3, IQR 1 to 4, [p = 0.026]). In the patients with CRS, elevated serum D-dimer level and higher baseline NIHSS score were independently associated with unfavorable functional outcome at 3 months (adjusted odds ratio [aOR]: 1.524, 95% confidence interval [CI]: 1.043–2.226; aOR: 1.264, 95% CI: 1.010–1.582, respectively). Conclusions MT is an appropriate therapeutic treatment for revascularization in CRS patients. However, elevated serum D-dimer levels and higher baseline NIHSS scores were independent predictors of unfavorable outcome. Further research is warranted to evaluate the significance of these predictors.This research was supported by a fund (#2020ER620200) by the Korea Centers for Disease Control & Prevention and Clinical Research Society for Stroke, Republic of Korea

High triglyceride-glucose index is associated with subclinical cerebral small vessel disease in a healthy population: a cross-sectional study

The triglyceride-glucose (TyG) index is a marker of insulin resistance (IR) and has been associated with various metabolic syndromes, cardiovascular diseases, and cerebrovascular diseases. However, limited information is available regarding its association with subclinical cerebral small vessel disease (cSVD). In this study, we evaluated the relationship between the TyG index and cSVD, including silent brain infarcts (SBIs) and white matter hyperintensity (WMH). We assessed health check-up participants aged 40–79years from 2006 to 2013. The TyG index was calculated using the log scale of fasting triglyceride (mg/dL) × fasting glucose (mg/dL)/2. The Homeostatic Model Assessment for Insulin Resistance (HOMA-IR) was also calculated. This was compared with two insulin surrogates and cSVD as another IR indicator and compared the association between two insulin surrogates and cSVD. SBI was measured for both prevalence and burden. The WMH volume was quantitatively rated using a computer-assisted semi-automated technique. Results A total of 2615 participants were evaluated (median age: 56years, male sex: 53%). In the multivariable logistic regression analysis, the TyG index was seen to be associated with SBI prevalence (adjusted odds ratio: 1.39; 95% confidence interval [CI] = 1.06–1.81). Further quantitative analyses showed a positive dose–response relationship between the TyG index and SBI burden (P for trend = 0.006). In multivariable linear regression analysis, the TyG index was also found to be related to the volume of WMH (β = 0.084; 95% CI = 0.013 to 0.154). Additionally, the TyG index showed a similar or slightly stronger association with the prevalence of SBI and the volume of WMH than did HOMA-IR. A high TyG index was associated with a higher prevalence and burden of cSVD in a neurologically healthy population. This marker of IR could be a convenient and useful predictor of cSVD

Uncovering transcriptional reprogramming during callus development in soybean: insights and implications

Callus, a valuable tool in plant genetic engineering, originates from dedifferentiated cells. While transcriptional reprogramming during callus formation has been extensively studied in Arabidopsis thaliana, our knowledge of this process in other species, such as Glycine max, remains limited. To bridge this gap, our study focused on conducting a time-series transcriptome analysis of soybean callus cultured for various durations (0, 1, 7, 14, 28, and 42 days) on a callus induction medium following wounding with the attempt of identifying genes that play key roles during callus formation. As the result, we detected a total of 27,639 alterations in gene expression during callus formation, which could be categorized into eight distinct clusters. Gene ontology analysis revealed that genes associated with hormones, cell wall modification, and cell cycle underwent transcriptional reprogramming throughout callus formation. Furthermore, by scrutinizing the expression patterns of genes related to hormones, cell cycle, cell wall, and transcription factors, we discovered that auxin, cytokinin, and brassinosteroid signaling pathways activate genes involved in both root and shoot meristem development during callus formation. In summary, our transcriptome analysis provides significant insights into the molecular mechanisms governing callus formation in soybean. The information obtained from this study contributes to a deeper understanding of this intricate process and paves the way for further investigation in the field

Sex disparity in dialysis and kidney transplantation over 20 years in Korea

Background Sex disparity is prevalent in organ transplantations worldwide. This study aimed to understand sex disparities in dialysis and kidney transplantation in Korea over the last 20 years. Methods Data for incident dialysis, waiting list registration, and donors and recipients were retrospectively collected between January 2000 and December 2020 from the Korean Society of Nephrology end-stage renal disease registry and the database of the Korean Network for Organ Sharing. Data regarding the proportion of females for dialysis, waiting list, and kidney transplantation donors or recipients were analyzed using linear regression analysis. Results The average proportion of females on dialysis over the past 20 years was 40.5%. The proportion of females on dialysis was 42.8% in 2000, and decreased to 38.2% in 2020, showing a decreasing trend. The average proportion of women on the waiting list was 38.4%, which was lower than that for dialysis. The average proportion of female recipients in living donor kidney transplantation and female living donors were 40.1% and 53.2%, respectively. The overall proportion of female donors in living donor kidney transplantation showed an increasing trend. However, there was no change in the proportion of female recipients in living donor kidney transplantation. Conclusion Sex disparities in organ transplantation exist, including an increasing trend of female donors in living donor kidney transplantation. Further studies are needed to identify the biological and socioeconomic factors involved to resolve these disparities