Tailoring Hydrophobicity and Pore Environment in Physisorbents for Improved Carbon Dioxide Capture under High Humidity.

CALF-20, a Zn-triazolate-based metal-organic framework (MOF), is one of the most promising adsorbent materials for CO2 capture. However, competitive adsorption of water severely limits its performance when the relative humidity (RH) exceeds 40%, limiting the potential implementation of CALF-20 in practical settings where CO2 is saturated with moisture, such as postcombustion flue gas. In this work, three newly designed MOFs related to CALF-20, denoted as NU-220, CALF-20M-w, and CALF-20M-e that feature hydrophobic methyltriazolate linkers, are presented. Inclusion of methyl groups in the linker is proposed as a strategy to improve the uptake of CO2 in the presence of water. Notably, both CALF-20M-w and CALF-20M-e retain over 20% of their initial CO2 capture efficiency at 70% RH─a threshold at which CALF-20 shows negligible CO2 uptake. Grand canonical Monte Carlo simulations reveal that the methyl group hinders water network formation in the pores of CALF-20M-w and CALF-20M-e and enhances their CO2 selectivity over N2 in the presence of a high moisture content. Moreover, calculated radial distribution functions indicate that introducing the methyl group into the triazolate linker increases the distance between water molecules and Zn coordination bonds, offering insights into the origin of the enhanced moisture stability observed for CALF-20M-w and CALF-20M-e relative to CALF-20. Overall, this straightforward design strategy has afforded more robust sorbents that can potentially meet the challenge of effectively capturing CO2 in practical industrial applications.

Effective Strategy toward Obtaining Reliable Breakthrough Curves of Solid Adsorbents.

Metal-organic frameworks (MOFs) have demonstrated their versatility in a wide range of applications, including chemical separation, gas capture, and storage. In industrial adsorption processes, MOFs are integral to the creation of selective gas adsorption fixed beds. In this context, the assessment of their separation performance under relevant conditions often relies on breakthrough experiments. One aspect frequently overlooked in these experiments is the shaping of MOF powders, which can significantly impact the accuracy of breakthrough results. In this study, we present an approach for immobilizing MOF particles on the surface of glass beads (GBs) utilizing trimethylolpropane triglycidyl ether (TMPTGE) as a binder, leading to the creation of MOF@GB materials. We successfully synthesized five targeted MOF composites, namely, SIFSIX-3-Ni@GB, CALF-20@GB, UiO-66@GB, HKUST-1@GB, and MOF-808@GB, each possessing distinct pore sizes and structural topologies. Characterization studies employing powder X-ray diffraction and adsorption isotherm analyses demonstrated that MOFs@GB retained their crystallinity and 73-90% of the Brunauer-Emmett-Teller area of their parent MOFs. Dynamic breakthrough experiments revealed that, in comparison to their parent MOFs, MOF@GB configurations enhanced the accuracy of breakthrough measurements by mitigating pressure buildup and minimizing reductions in the gas flow rate. This work underscores the significance of meticulous experimental design, specifically in shaping MOF powders, to optimize the efficacy of breakthrough experiments. Our proposed strategy aims to provide a versatile platform for MOF powder processing, thereby facilitating more reliable breakthrough experiments.

Successful management of massive digoxin overdose using DIGIFab and therapeutic plasma exchange: a case report.

BACKGROUND: Despite the efficacy and safety of DIGIFab, it is relatively expensive and has limited availability. In addition, alternative interventions, such as therapeutic plasma exchange, may need to be considered in massive digoxin overdoses. Although few case reports describe its efficacy. CASE PRESENTATION: We report a case of a 17-year-old white male patient brought by family members to our emergency department in Riyadh, Saudi Arabia. After intentionally ingesting 48 mg of digoxin tablets to commit suicide, the patient's initial digoxin serum level was 8.04 ng/mL. The patient was resuscitated in the emergency department. After admission to the intensive care unit, the patient underwent therapeutic plasma exchange, because of insufficient DIGIFab doses. Afterward, the serum digoxin levels drastically decreased, and his symptoms reverted. The patient was successfully managed and discharged 7 days after admission. CONCLUSION: Despite insufficient evidence and a limited number of case reports describing the use of extracorporeal treatment in digoxin overdose, we noted the significant impact of therapeutic plasma exchange on our patient. However, therapeutic plasma exchange's use in routine treatment requires stronger evidence to confirm its benefits.

Perception, Knowledge, Indications, and Future Prospects of Point-of-Care Ultrasound Among Medical Students in Saudi Arabia.

Introduction Point-of-care ultrasound (POCUS) has become integral across medical specialties globally, addressing clinical queries, guiding procedures, and bridging the gap between physical examination and advanced imaging. Early ultrasound training for medical students enhances clinical decision-making and reduces diagnostic errors. Aims To evaluate the knowledge and attitude of senior medical students towards POCUS and to assess knowledge gaps and difficulties encountered by senior medical students to assist in the development of future curricula. Methodology This is an observational, cross-sectional approach to evaluate knowledge, attitude, and practice of POCUS among senior medical students in the Kingdom of Saudi Arabia. The study was conducted from January to September 2023. An electronic questionnaire was distributed through online platforms utilizing medical school databases across various regions. The survey encompassed sociodemographics, training methods, diagnostic indications, and participants' self-reported proficiency and attitudes toward POCUS. The data was chiefly collected using the Likert scale. Descriptive statistics were used to describe the quantitative and categorical variables. Bivariate and multivariate analyses were used to examine correlations. Results A total of 359 senior medical students completed the survey. Most responders were females (57.9%) with the predominating age group being ≤ 24 years (83.6%). The students predominantly were from the Central region of Saudi Arabia (75.5%). Ultrasound training varied among responders; 31.5% received formal courses (median duration: two hours) and 23.4% informal courses (median duration: four hours). Around 17.3% practiced POCUS self-teaching (median duration: four hours). A total of 3.6% had formal POCUS accreditation. A gargantuan 82.2% never used POCUS in their attached hospital for a variety of reasons. Multivariable logistic binary regression analysis showed a positive correlation between students' self-teaching of POCUS and their perceived difficulty performing an ultrasound examination for patients in daily practice. Discussion A comparable study was done at King Saud bin Abdulaziz University for Health Sciences (KSAU-HS) in 2022 surveying 229 senior medical students by Rajendram et al. In their study, 21.4% completed formal courses and 12.7% took informal courses. While many students in our study were not exposed to POCUS (82.2%), KSAU-HS reported a higher percentage reaching 94.8%. A study by Russel et al. demonstrated more than half of 154 surveyed medical schools in the United States have implemented POCUS into their students' curriculum. Conclusion POCUS stands as a valuable skill that can enhance the educational journey of undergraduate medical students. Considering that a significant number of participants haven't yet taken formal medical school courses suggests a lack of awareness about its significance in the medical field. Offering additional courses with practical components could enhance the proficiency, confidence, and outlook of medical students toward POCUS.

Effects of prenatal propofol exposure on postnatal development in rats.

Preclinical studies suggest that propofol may cause damage to immature neurons. However, the effect of maternal propofol exposure on the neuronal development of the offspring is largely unknown. In this study, pregnant rats were assigned to receive continuous infusion of saline (control) or propofol for 1 h (1HP) or 2 h (2HP) on gestational day 18. An additional group (lipid) was assigned to receive continuous infusion of intralipid fat emulsion (vehicle of propofol) for 2 h. Pups were then tested on the appearance and progression of sensory and physical motor abilities between postnatal day 1 (P1) and P28. The brain and body weights of pups from 2HP group on P10 were significantly lower than those from the saline control group, although they were the same in all four groups at birth (P0). Pups from 1HP and 2HP groups, but not lipid group, showed slower maturation of eyes (delayed opening) and several neurological reflexes (hindlimb reflex, righting reflex); they also showed delayed improvement in execution on gait reflex and inclined board tests. The forelimb reflex and negative geotaxis were also delayed in 2HP group. All parameters examined except body weight of 2HP pups recovered to normal levels by P28. We conclude that administration of propofol to pregnant rats leads to retardation in physical and neurological reflex development in their offspring.

Propofol exposure in pregnant rats induces neurotoxicity and persistent learning deficit in the offspring.

Propofol is a general anesthetic widely used in surgical procedures, including those in pregnant women. Preclinical studies suggest that propofol may cause neuronal injury to the offspring of primates if it is administered during pregnancy. However, it is unknown whether those neuronal changes would lead to long-term behavioral deficits in the offspring. In this study, propofol (0.4 mg/kg/min, IV, 2 h), saline, or intralipid solution was administered to pregnant rats on gestational day 18. We detected increased levels of cleaved caspase-3 in fetal brain at 6 h after propofol exposure. The neuronal density of the hippocampus of offspring was reduced significantly on postnatal day 10 (P10) and P28. Synaptophysin levels were also significantly reduced on P28. Furthermore, exploratory and learning behaviors of offspring rats (started at P28) were assessed in open-field trial and eight-arm radial maze. The offspring from propofol-treated dams showed significantly less exploratory activity in the open-field test and less spatial learning in the eight-arm radial maze. Thus, this study suggested that propofol exposure during pregnancy in rat increased cleaved caspsase-3 levels in fetal brain, deletion of neurons, reduced synaptophysin levels in the hippocampal region, and persistent learning deficits in the offspring.