Molecular sieving membranes with sufficient and uniform nanochannels that break the permeability-selectivity trade-off are desirable for energy-efficient gas separation, and the arising ...two-dimensional (2D) materials provide new routes for membrane development. However, for 2D lamellar membranes, disordered interlayer nanochannels for mass transport are usually formed between randomly stacked neighboring nanosheets, which is obstructive for highly efficient separation. Therefore, manufacturing lamellar membranes with highly ordered nanochannel structures for fast and precise molecular sieving is still challenging. Here, we report on lamellar stacked MXene membranes with aligned and regular subnanometer channels, taking advantage of the abundant surface-terminating groups on the MXene nanosheets, which exhibit excellent gas separation performance with H
permeability >2200 Barrer and H
/CO
selectivity >160, superior to the state-of-the-art membranes. The results of molecular dynamics simulations quantitatively support the experiments, confirming the subnanometer interlayer spacing between the neighboring MXene nanosheets as molecular sieving channels for gas separation.
To adapt to the climate of the Tibetan Plateau, vernacular houses possess passive solar features. Although numerous studies have investigated Tibetan houses, only a few case studies have considered ...the influence of historical evolution, especially in the Tibetan area outside of Tibet. Via a field survey, literature review, and computer simulations, the external appearance, building envelope, shading and opening of 40 Gyalrong houses were investigated. According to the study findings, first, Gyalrong Tibetan houses are typically blockhouses facing south or east, with flat roofs and compact volumes. Second, the building envelopes mainly reflect the construction materials and related vernacular architecture techniques. Third, the indoor thermal and lighting environment improves due to the increasing window-to-wall ratio and the adoption of sunspace. The quantitative investigation shows that Gyalrong Tibetan houses express the bottom-up adaptation of architecture not only in terms of natural conditions but also in the evolution of building materials.
This is the first monograph on codebooks and linear codes from difference sets and almost difference sets. It aims at providing a survey of constructions of difference sets and almost difference sets ...as well as an in-depth treatment of codebooks and linear codes from difference sets and almost difference sets. To be self-contained, this monograph covers necessary mathematical foundations and the basics of coding theory. It also contains tables of best BCH codes and best cyclic codes over GF(2) and GF(3) up to length 125 and 79, respectively. This repository of tables can be used to benchmark newly constructed cyclic codes. This monograph is intended to be a reference for postgraduates and researchers who work on combinatorics, or coding theory, or digital communications.
The phagocytosis and homeostasis of microglia play an important role in promoting blood clearance and improving prognosis after subarachnoid hemorrhage (SAH). LC3-assocaited phagocytosis (LAP) ...contributes to the microglial phagocytosis and homeostasis via autophagy-related components. With RNA-seq sequencing, we found potential signal pathways and genes which were important for the LAP of microglia.
We used an in vitro model of oxyhemoglobin exposure as SAH model in the study. RNA-seq sequencing was performed to seek critical signal pathways and genes in regulating LAP. Bioparticles were used to access the phagocytic ability of microglia. Western blot (WB), immunoprecipitation, quantitative polymerase chain reaction (qPCR) and immunofluorescence were performed to detect the expression change of LAP-related components and investigate the potential mechanisms.
In vitro SAH model, there were increased inflammation and decreased phagocytosis in microglia. At the same time, we found that the LAP of microglia was inhibited in all stages. RNA-seq sequencing revealed the importance of P38 MAPK signal pathway and DAPK1 in regulating microglial LAP. P38 was found to regulate the expression of DAPK1, and P38-DAPK1 axis was identified to regulate the LAP and homeostasis of microglia after SAH. Finally, we found that P38-DAPK1 axis regulated expression of BECN1, which indicated the potential mechanism of P38-DAPK1 axis regulating microglial LAP.
P38-DAPK1 axis regulated the LAP of microglia via BECN1, affecting the phagocytosis and homeostasis of microglia in vitro SAH model. Video Abstract.
Least squares is an important method for solving linear fitting problems and quadratic optimization problems. This paper explores the properties of the least squares methods and the multi-innovation ...least squares methods. It demonstrates lemmas and theorems about the least squares and multi-innovation least squares parameter estimation algorithms after reviewing and surveying some important contributions in the area of system identification, such as the auxiliary model identification idea, the multi-innovation identification theory, the hierarchical identification principle, the coupling identification concept and the filtering identification idea. The results of the least squares and multi-innovation least squares algorithms for linear regressive systems with white noises can be extended to other systems with colored noises.
Online Social Networks generate a prodigious wealth of real-time information at an incessant rate. In this paper we study the empirical data that crawled from Twitter to describe the topology and ...information spreading dynamics of Online Social Networks. We propose a measurement with three measures to state the efforts of users on Twitter to get their information spreading, based on the unique mechanisms for information retransmission on Twitter. It is noticed that small fraction of users with special performance on participation can gain great influence, while most other users play a role as middleware during the information propagation. Thus a community analysis is performed and four categories of users are found with different kinds of participation that cause the information dissemination dynamics. These suggest that exiting topological measures alone may reflect little about the influence of individuals and provide new insights for information spreading.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Heterogeneous reactions of mineral dust aerosol with trace gases in the atmosphere could directly and indirectly affect tropospheric oxidation capacity, in addition to aerosol composition and ...physicochemical properties. In this article we provide a comprehensive and critical review of laboratory studies of heterogeneous uptake of OH, NO3, O3, and their directly related species as well (including HO2, H2O2, HCHO, HONO, and N2O5) by mineral dust particles. The atmospheric importance of heterogeneous uptake as sinks for these species is assessed (i) by comparing their lifetimes with respect to heterogeneous reactions with mineral dust to lifetimes with respect to other major loss processes and (ii) by discussing relevant field and modeling studies. We have also outlined major open questions and challenges in laboratory studies of heterogeneous uptake by mineral dust and discussed research strategies to address them in order to better understand the effects of heterogeneous reactions with mineral dust on tropospheric oxidation capacity.
Abstract
Background
The Shanghai Epidemiological Survey of Dementia and Alzheimer’s Disease (SESD)1 and the Shanghai Aging Study (SAS)2 are geographically defined population‐based studies established ...in the same resident district in 1987 and 2010. We attempted to explore the secular trend of dementia mortality through these two cohort studies conducted two decades apart.
Method
We examined the changes in 5‐year mortality of dementia (i.e. Alzheimer’s disease AD, vascular dementia VD, and all dementia) by analyzing survival data of participants aged≥65 years from the prospective stages of SESD (1987‐1992) 1 and SAS (2010‐2015). Mortality rate (MR), case fatality rate (CFR), and standardized mortality ratio (SMR) in SAS were adjusted by the sex, age, and education‐structured population data in SESD.
Result
Compared to SESD (n = 3531), participants in SAS (n = 2342) were older and more educated, and with a higher prevalence of hypertension, diabetes, stroke, cancer, and kidney disease. The adjusted 5‐year MRs of AD (0.76% vs. 2.24%; OR, 95%CI 0.34, 0.20‐0.57), VD (0.37% vs. 1.16%; OR 0.33,0.16‐0.68), and all dementia (1.23% vs. 3.74%; OR 0.32, 0.22‐0.48) in SAS were lower than that in SESD. The same trend of the 5‐year CFRs was also observed in AD (23.3% vs. 62.2%; OR 0.19, 0.10‐0.35), VD (48.7% vs. 77.4%; OR 0.29, 0.10‐0.90), and all dementia (61.0% vs. 70.6%; OR 0.21, 0.12‐0.35). When taking into account that the 5‐year all‐cause mortality rate in total participants also decreased from 20.33% in SESD to 9.14% in SAS (OR 0.39, 0.34‐0.46), the SMRs of all dementia (3.30 vs. 3.20) and AD (3.06 vs. 2.54) in SAS were similar with that in SESD, while an increasing trend was shown in VD (3.81 vs. 5.32).
Conclusion
We observed a decreasing trend of dementia mortality, and vascular dementia still induced a higher threat to life loss over 20 years in this older Chinese population.
References: 1. Katzman R, et al. The malignancy of dementia. Predictors of mortality in clinically diagnosed dementia in a population survey of Shanghai, China. Arch Neurol. 1994;51:1220‐1225.
2. Ding D, et al. The Shanghai Aging Study: study design, baseline characteristics, and prevalence of dementia. Neuroepidemiology.2014;43:114‐122. 3.
To evaluate the growing literature on the built environment and physical activity/obesity, we conducted a review of review papers. Through a systematic search, we identified 36 reviews that met the ...inclusion criteria and evaluated these reviews based on key information provided, review methodology, and specificity regarding measurement. We also analyzed research gaps and areas of improvement identified by previous reviews and propose a research agenda. Future studies should develop complex conceptual and statistical models that include moderators and mediators, improve objective and perceived measures of the built environment, and strengthen evidence of causality through better research designs.
Quantum heat engines are expected to outperform the classical counterparts due to quantum coherences involved. Here we experimentally execute a single-ion quantum heat engine and demonstrate, for the ...first time, the dynamics and the enhanced performance of the heat engine originating from the Liouvillian exceptional points (LEPs). In addition to the topological effects related to LEPs, we focus on thermodynamic effects, which can be understood by the Landau-Zener-Stückelberg process under decoherence. We witness a positive net work from the quantum heat engine if the heat engine cycle dynamically encircles a LEP. Further investigation reveals that a larger net work is done when the system is operated closer to the LEP. We attribute the enhanced performance of the quantum heat engine to the Landau-Zener-Stückelberg process, enabled by the eigenenergy landscape in the vicinity of the LEP, and the exceptional point-induced topological transition. Therefore, our results open new possibilities toward LEP-enabled control of quantum heat engines and of thermodynamic processes in open quantum systems.
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