Sustainable organic electrode materials, as promising alternatives to conventional inorganic electrode materials for sodium‐ion batteries (SIBs), are still challenging to realize long‐lifetime and ...high‐rate batteries because of their poor conductivity, limited electroactivity, and severe dissolution. It is also urgent to deeply reveal their electrochemical mechanism and evolution processes. A porous organic polymer (POP) with a conjugated and hierarchical structure is designed and synthesized here. The unique molecule and structure endow the POP with electron delocalization, high ionic diffusivity, plentiful active sites, exceptional structure stability, and limited solubility in electrolytes. When evaluated as an anode for SIBs, the POP exhibits appealing electrochemical properties regarding reversible capacity, rate behaviors, and long‐duration life. Importantly, using judiciously combined experiments and theoretical computation, including in situ transmission electron microscopy (TEM), and ex situ spectroscopy, we reveal the Na‐storage mechanism and dynamic evolution processes of the POP, including 12‐electron reaction process with Na, low volume expansion (125–106% vs the initial 100%), and stable composition and structure evolution during repeating sodiation/de‐sodiation processes. This quantitative design for ultrafast and highly durable sodium storage in the POP could be of immediate benefit for the rational design of organic electrode materials with ideal electrochemical properties.
Developing sustainable organic electrode materials with high‐rate capability and satisfactory cycle lifespan is one of the key parameters for exploiting the next‐generation sodium‐ion batteries at practical levels. In this work, a facile polymerization strategy is developed for preparing a porous organic polymer with a hierarchical structure and limited volume expansion that enables ultrafast and highly durable sodium storage.
The vigorous development of efficient platinum group metal‐free catalysts is considerably important to facilitate the universal application of proton exchange membrane fuel cells. Although ...nitrogen‐coordinated atomic iron intercalated in carbon matrix (Fe–N–C) catalysts exhibit promising catalytic activity, the performance in fuel cells, especially the short lifetime, remains an obstacle. Herein, a highly‐active Fe–N–C catalyst with a power density of >1 w cm‐2 and prolonged discharge stability with a current density of 357 mA cm‐2 after 40 h of constant voltage discharge at 0.7 V in H2–O2 fuel cells using a controllable and efficient N–C coating strategy is developed. It is clarified that a thicker N–C coating may be more favorable to enhance the stability of Fe–N–C catalysts at the expense of their catalytic activity. The stability enhancement mechanism of the N–C coating strategy is proven to be the synergistic effect of reduced carbon corrosion and iron loss. It is believed that these findings can contribute to the development of Fe–N–C catalysts with high activity and long lifetimes.
Development of highly‐catalytic and long‐term stable Fe–N–C catalyst using a controllable and efficient N–C coating strategy. The correlation between the thickness of N–C coatings and electrochemical performance is investigated. The stability improvement mechanism of N–C coating is identified to reduce carbon corrosion and iron leaching.
We examine the role of agricultural productivity as a determinant of China's post-reform economic growth and sectoral reallocation. Using microeconomic farm-level data, and treating labor as a highly ...differentiated input, we find that the labor input in agriculture decreased by 5% annually and agricultural TFP grew by 6.5%. Using a calibrated two-sector general equilibrium model, we find that agricultural TFP growth: (i) accounts for the majority of output and employment reallocation toward non-agriculture; (ii) contributes (at least) as much to aggregate and sectoral economic growth as non-agricultural TFP growth; and (iii) influences economic growth primarily by reallocating workers to the non-agricultural sector, where rapid physical and human capital accumulation are currently taking place.
Fe–N–C Catalysts
In article number 2207671, Jia Li, Jianguo Liu, and co‐workers develop a highly‐catalytic Fe–N–C catalyst with a power density of >1 w cm−2 and prolonged lifetime (>40 h) using a ...controllable and efficient N–C coating strategy. The authors investigate the correlation between coating thickness and electrochemical performance. They also identify the stability improvement mechanism to the reduced carbon corrosion and iron loss in catalyst.
Background
Triple negative breast cancer (TNBC) is the most aggressive subtype with the worst prognosis. The role of profilin 2
(
PFN2) in TNBC is very controversial. The current study is to explore ...the role of PFN2 in TNBC.
Methods
PFN2 expression in TNBC and normal breast tissues were evaluated by immunohistochemical analysis. The association between PFN2 expression and prognosis in TNBC patients was analyzed from the TCGA database. A cell counting kit-8 (CCK8) assay was employed to investigate the effects of PFN2 in TNBC cell proliferations. The migration and invasion capability of TNBC cells was evaluated by transwell assays. Western blot was performed to assess the related protein expression of TGF-β/Smad signaling and epithelial to mesenchymal transition. Finally, TNBC xenografts were established to determine the tumorigenicity in vivo using female Nod/Scid mice.
Results
PFN2 is upregulated in TNBC and the higher expression was associated with worse survival. CCK8 assays and Transwell assays demonstrated that PFN2 promoted the proliferation, migration and invasion of TNBC cells. Smad2 and Smad3 were upregulated in PFN2 overexpressing TNBC cells, which further induced the process of epithelial‑to‑mesenchymal transition. Similarly, the overexpressing PFN2 TNBC cells exhibited stronger tumorigenicity in vivo.
Conclusions
Higher PFN2 expression is associated with a worse 10-year overall survival and relapse-free survival in breast cancer patients, as well as worse 10-year relapse-free survival in TNBC patients. PFN2 promotes the proliferation, migration and invasion of TNBC cells by regulating epithelial-to-mesenchymal transition.
A new decision rule based on net benefit per capita is proposed and exemplified with the aim of assisting policymakers in deciding whether to lockdown or reopen an economy—fully or partially—amidst a ...pandemic. Bayesian econometric models using Markov chain Monte Carlo algorithms are used to quantify this rule, which is illustrated via several sensitivity analyses. While we use COVID-19 data from the United States to demonstrate the ideas, our approach is invariant to the choice of pandemic and/or country. The actions suggested by our decision rule are consistent with the closing and reopening of the economies made by policymakers in Florida, Texas, and New York; these states were selected to exemplify the methodology since they capture the broad spectrum of COVID-19 outcomes in the U.S.
Motivated by the relatively infrequent but very large price spikes in the day-ahead and real-time energy markets operated by the Electric Reliability Council of Texas, this paper proposes an ...insurance that a small and risk-averse retailer in Texas (i.e., a retail electric provider (REP)) may buy to prevent financial insolvency caused by inadequate risk management. It also demonstrates the insurance’s practical design, pricing, and implementation. As participation in the REP’s procurement auction is voluntary, the insurance is mutually beneficial for the REP and the insurance seller. Hence, the proposed insurance is a newly developed wholesale market product that deserves consideration by REPs in Texas and competitive retailers elsewhere.
Human mesenchymal stem cells (hMSCs) can be differentiated into osteoblasts and adipocytes. During these processes, super enhancers (SEs) play important roles. Here, we performed comprehensive ...characterization of the SEs changes associated with adipogenic and osteogenic differentiation of hMSCs, and revealed that SEs changed more dramatically compared with typical enhancers. We identified a set of lineage-selective SEs, whose target genes were enriched with cell type-specific functions. Functional experiments in lineage-selective SEs demonstrated their specific roles in directed differentiation of hMSCs. We also found that some key transcription factors regulated by lineage-selective SEs could form core regulatory circuitry (CRC) to regulate each other's expression and control the hMSCs fate determination. In addition, we found that GWAS SNPs of osteoporosis and obesity were significantly enriched in osteoblasts-selective SEs or adipocytes-selective SEs, respectively. Taken together, our studies unveiled important roles of lineage-selective SEs in hMSCs differentiation into osteoblasts and adipocytes.
A novel methodology to model electricity prices and latent causes as endogenous, multivariate time-series is developed and is applied to the Texas energy market. In addition to exogenous factors like ...the type of renewable energy and system load, observed prices are also influenced by some combination of latent causes. For instance, prices may be affected by power outages, erroneous short-term weather forecasts, unanticipated transmission bottlenecks, etc. Before disappearing, these hidden, unobserved factors are usually present for a contiguous period of time, thereby affecting prices. Using our system-wide latent factor model, we find that: (a) latent causes have a highly significant impact on prices in Texas; (b) the estimated latent factor series strongly and positively correlates to system-wide prices during peak and off-peak hours; (c) the merit-order effect of wind significantly dampens prices, regardless of region and time of day; and (d) the nuclear baseload generation also significantly lowers prices during a 24-h period in the entire system.
About 15% of lung cancers in men and 53% in women are not attributable to smoking worldwide. The aim was to develop and validate a simple and non-invasive model which could assess and stratify lung ...cancer risk in non-smokers in China.
A large-sample size, population-based study was conducted under the framework of the Cancer Screening Program in Urban China (CanSPUC). Data on the lung cancer screening in Henan province, China, from October 2013 to October 2019 were used and randomly divided into the training and validation sets. Related risk factors were identified through multivariable Cox regression analysis, followed by establishment of risk prediction nomogram. Discrimination area under the curve (AUC) and calibration were further performed to assess the validation of risk prediction nomogram in the training set, and then validated by the validation set.
A total of 214,764 eligible subjects were included, with a mean age of 55.19 years. Subjects were randomly divided into the training (107,382) and validation (107,382) sets. Elder age, being male, a low education level, family history of lung cancer, history of tuberculosis, and without a history of hyperlipidemia were the independent risk factors for lung cancer. Using these six variables, we plotted 1-year, 3-year, and 5-year lung cancer risk prediction nomogram. The AUC was 0.753, 0.752, and 0.755 for the 1-, 3- and 5-year lung cancer risk in the training set, respectively. In the validation set, the model showed a moderate predictive discrimination, with the AUC was 0.668, 0.678, and 0.685 for the 1-, 3- and 5-year lung cancer risk.
We developed and validated a simple and non-invasive lung cancer risk model in non-smokers. This model can be applied to identify and triage patients at high risk for developing lung cancers in non-smokers.
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