Heteroatom-Doped Defects Anchoring Nano-Pt for High-Stability and Low-Humidity Proton Exchange Membrane Fuel Cell.

To meet the ever-increasing demand of proton exchange membrane fuel cell (PEMFC), it is necessary to carry out structure optimization for low-cost and high-stability oxygen reduction reaction (ORR) catalysts. Herein, a zeolitic imidazolate framework (ZIF)-derived carbon material with a mass of heteroatoms and defects is developed and serves as advanced support for nano-Pt-based ORR catalysts. This unique structure enhances the interaction between nano-Pt and support, leading to higher ORR intrinsic activity. During fuel cell applications, it demonstrates impressive water-retaining capacity and electrochemical stability. Under H2-O2 supply without cathode humidification, this catalyst achieves high mass activity of 0.475 A mgPt -1, with only 7.4% attenuation in maximum power density after 20 000 cycles of accelerated durability test, highlighting its remarkable potential for fuel cell applications. Physicochemical characterization and theoretical simulation reveal the crucial anchoring effect of heteroatom-doped defects to nano-Pt, providing valuable insights for further ORR catalyst design and PEMFC applications.

Achieving High Dispersion of Pd in Small-Pore Zeolite SSZ-13: A High-Efficiency Low-Temperature NOx Adsorber.

Passive NO x adsorber (PNA) materials are primarily considered for reducing nitrogen oxide emissions during the low-temperature cold start of a motor vehicle. Pd/SSZ-13 has attracted considerable attention because of its outstanding hydrothermal stability and sulfur resistance. Optimizing the dispersion of precious metal Pd in Pd/SSZ-13 is crucial for enhancing PNA performance and nitrogen oxide adsorption capability. In this study, we prepared Pd/SSZ-13 using different methods and evaluated their influence on the NO x adsorption capability. The characterization results show that the dispersion of precious metal Pd in the Pd/SSZ-13 catalyst prepared by the quantitative ion-exchange method is as high as 92.13%, and the loading amount is as high as 98.93%. Pd predominantly exists as Pd2+, achieving near-total loading and further improving the catalyst's NO x adsorption capacity. This study offers innovative approaches and methods for applying Pd/SSZ-13 as a PNA material, serving as a reference for its further optimization and performance enhancement. Continued research into the preparation and adsorption performance of Pd/SSZ-13 materials could offer solutions to reduce motor vehicle nitrogen oxide emissions.

The link between initial cardiac rhythm and survival outcomes in in-hospital cardiac arrest using propensity score matching, adjustment, and weighting.

The association between the initial cardiac rhythm and short-term survival in patients with in-hospital cardiac arrest (IHCA) has not been extensively studied despite the fact that it is thought to be a prognostic factor in patients with out-of-hospital cardiac arrest. This study aimed to look at the relationship between initial shockable rhythm and survival to hospital discharge in individuals with IHCA. 1516 adults with IHCA who received chest compressions lasting at least two minutes at the National Taiwan University Hospital between 2006 and 2014 made up the study population. Propensity scores were estimated using a fitted multivariate logistic regression model. Various statistical methodologies were employed to investigate the association between shockable rhythm and the probability of survival to discharge in patients experiencing IHCA, including multivariate adjustment, propensity score adjustment, propensity score matching, and logistic regression based on propensity score weighting. In the original cohort, the multivariate-adjusted odds ratio (OR) was 2.312 (95% confidence interval [CI]: 1.515-3.531, P < 0.001). In additional propensity score adjustment, the OR between shockable rhythm and the probability of survival to hospital discharge in IHCA patients was 2.282 (95% CI: 1.486, 3.504, P < 0.001). The multivariate-adjusted logistic regression model analysis revealed that patients with shockable rhythm had a 1.761-fold higher likelihood of surviving to hospital release in the propensity score-matched cohort (OR = 2.761, 95% CI: 1.084-7.028, P = 0.033). The multivariate-adjusted OR of the inverse probability for the treatment-weighted cohort was 1.901 (95% CI: 1.507-2.397, P < 0.001), and the standardized mortality ratio-weighted cohort was 2.692 (95% CI: 1.511-4.795, P < 0.001). In patients with in-hospital cardiac arrest, Initial cardiac rhythm is an independent predictor of survival to hospital discharge. Depending on various statistical methods, patients with IHCA who have a shockable rhythm have a one to two fold higher probability of survival to discharge than those who have a non-shockable rhythm. This provides a reference for optimizing resuscitation decisions for IHCA patients and facilitating clinical communication.

Link between triglyceride-glucose-body mass index and future stroke risk in middle-aged and elderly chinese: a nationwide prospective cohort study.

OBJECTIVE: Current literature is deficient in robust evidence delineating the correlation between the triglyceride glucose-body mass index (TyG-BMI) and the incidence of stroke. Consequently, this investigation seeks to elucidate the potential link between TyG-BMI and stroke risk in a cohort of middle-aged and senior Chinese individuals. METHODS: This study employs longitudinal data from four waves of the China Health and Retirement Longitudinal Study (CHARLS) conducted in 2011, 2013, 2015, and 2018, encompassing 8,698 participants. The CHARLS cohort was assembled using a multistage probability sampling technique. Participants underwent comprehensive evaluations through standardized questionnaires administered via face-to-face interviews. Our analytic strategy involved the application of Cox proportional hazards regression models to investigate the association between TyG-BMI and the risk of stroke. To discern potential non-linear relationships, we incorporated Cox proportional hazards regression with smooth curve fitting. Additionally, we executed a battery of sensitivity and subgroup analyses to validate the robustness of our findings. RESULTS: Our study utilized a multivariate Cox proportional hazards regression model and found a significant correlation between the TyG-BMI and the risk of stroke. Specifically, a 10-unit increase in TyG-BMI corresponded to a 4.9% heightened risk of stroke (HR = 1.049, 95% CI 1.029-1.069). The analysis also uncovered a non-linear pattern in this relationship, pinpointed by an inflection point at a TyG-BMI value of 174.63. To the left of this inflection point-meaning at lower TyG-BMI values-a 10-unit hike in TyG-BMI was linked to a more substantial 14.4% rise in stroke risk (HR 1.144; 95% CI 1.044-1.253). Conversely, to the right of the inflection point-at higher TyG-BMI values-each 10-unit increment was associated with a smaller, 3.8% increase in the risk of stroke (HR 1.038; 95% CI 1.016-1.061). CONCLUSIONS: In the middle-aged and elderly Chinese population, elevated TyG-BMI was significantly and positively associated with stroke risk. In addition, there was also a specific non-linear association between TyG-BMI and stroke (inflection point 174.63). Further reduction of TyG-BMI below 174.63 through lifestyle changes and dietary control can significantly reduce the risk of stroke.

Investigations of Li-Ion Battery Thermal Management Systems Based on Heat Pipes: A Review.

With increasing concerns about carbon emissions and the resulting climate impacts, Li-ion batteries have become one of the most attractive energy sources, especially in the transportation sector. For Li-ion batteries, an effective thermal management system is essential to ensure high-efficiency operation, avoid capacity degradation, and eliminate safety issues. Thermal management systems based on heat pipes can achieve excellent cooling performance in limited space and thus have been widely used for the temperature control of Li-ion batteries. In this paper, the thermal management systems of Li-ion batteries based on four types of heat pipes, i.e., flat single-channel heat pipes, oscillating heat pipes, flexible heat pipes, and microchannel heat pipes, are comprehensively reviewed based on the studies in the past 20 years. The effects of different influencing factors on the cooling performance and thermal runaway behavior of Li-ion batteries are thoroughly discussed in order to provide an in-depth understanding for researchers and engineers. It is concluded that for all types of thermal management systems based on heat pipes, water spray cooling could achieve better cooling performance than forced air cooling and water bath cooling, while its energy consumption is obviously smaller than forced air cooling. For thermal management systems based on oscillating heat pipes, improved heat transfer characteristics could be achieved by increasing the number of turns, using a relatively larger inner hydraulic diameter and using a length ratio between the evaporator and condenser higher than 1.0. Heat pipes fabricated by flexible materials suffer from permeation of noncondensable gases from ambient and leakage of working fluid. These issues could be partly resolved by adding thermal vias filled with metallic materials and covering the sealing part with indium coating or designing a multilayered structure with metallic materials in it. Moreover, the limitations and future trends of Li-ion battery thermal management systems based on heat pipes are presented. It is pointed out that the thermal runaway behavior and heating performance of battery thermal management systems based on heat pipes should be further elaborated. The analysis of this paper could provide valuable support for future investigations on Li-ion battery thermal management systems based on heat pipes; it could also guide the choice and design of Li-ion battery thermal management systems based on heat pipes in commercial use.

A smartphone-based online tool for prehospital self-triage of COVID-19.

The COVID-19 epidemic has swept across China and spread to other countries. The rapid spreading of COVID-19 and panic combined with the lack of a hierarchical medical system in China have resulted in a huge number of hospital visiting which are overwhelming local medical system and increasing the incidence of cross infection. To meliorate this situation, we adopted the management concept of the system of Tiered Diagnosis and Treatment and developed an online tool for self-triage based on the mostly used multi-purpose smartphone app Wechat in China. This online tool helps people perform self-triage so that they can decide whether to quarantine at home or visit hospital. This tool further provides instructions for home quarantine and help patients make an appointment online if hospital visiting suggested. This smartphone application can reduce the burden on hospitals without losing the truly COVID-19 patients and protect people from the danger of cross infection.

A novel mechanism for poisoning of metal oxide SCR catalysts: base-acid explanation correlated with redox properties.

A novel mechanism is proposed for the poisoning effect of acid gases and N2O formation on SCR catalysts involving base-acid properties correlated with redox ability of M-O or M-OH (M = Ce or V) of metal oxides and the strength of their basicity responsible for resistance to HCl and SO2 at medium and low temperatures.