Ferroptosis is a recently identified, iron-regulated, non-apoptotic form of cell death. It is characterized by cellular accumulation of lipid reactive oxygen species that ultimately leads to ...oxidative stress and cell death. Although first identified in cancer cells, ferroptosis has been shown to have significant implications in several neurologic diseases, such as ischemic and hemorrhagic stroke, Alzheimer’s disease, and Parkinson’s disease. This review summarizes current research on ferroptosis, its underlying mechanisms, and its role in the progression of different neurologic diseases. Understanding the role of ferroptosis could provide valuable information regarding treatment and prevention of these devastating diseases.
Ligand‐protected gold nanoclusters (AuNCs) have emerged as a new class of electrochemiluminescence (ECL) luminophores for their interesting catalytic and emission properties, although their quantum ...yield (ΦECL) in aqueous medium is low with a poor mechanistic understanding of the ECL process. Now it is shown that drying AuNCs on electrodes enabled both enhanced electrochemical excitation by an electrocatalytic effect, and enhanced emission by aggregation‐induced ECL (AIECL) for 6‐aza‐2‐thiothymine (ATT) protected AuNCs with triethylamine (TEA) as a coreactant. The dried ATT‐AuNCs/TEA system resulted in highly stable visual ECL with a ΦECL of 78 %, and a similar enhancement was also achieved with methionine‐capped AuNCs. The drying enabled dual‐enhancement mechanism has solved a challenging mechanistic problem for AuNC ECL probes, and can guide further rational design of ECL emitters.
Drying enabled the electrocatalytic excitation and aggregation‐induced emission of ligand‐capped gold nanoclusters (AuNCs), allowing a record high solid‐phase electrochemiluminescence (ECL) yield of 78 % and visual ECL. This work supports the in‐depth design and study of ECL in AuNCs and other materials in aqueous solutions.
Limited constraints on Cr isotope fractionation during weathering and river transport is currently a gap in our understanding of the chromium (Cr) isotope system, which is an emerging proxy in ...environmental and paleoenvironmental studies. Here, we investigate Cr mobility and isotope fractionation from the temperate Connecticut River, USA, including Cr concentrations and isotopic compositions of river water, suspended particles, riverbed sediments, and weathering profiles. The δ53Cr values of the Connecticut River water range from −0.17‰ to +0.92‰, which are similar to or higher than the weathered rocks in the catchment (−0.08‰ to −0.29‰). We find seasonal variations in dissolved δ53Cr values in some but not all tributaries, suggesting that dissolved δ53Cr is not a simple function of seasonality but may also be influenced by sub-catchment heterogeneity in lithology. In contrast to dissolved Cr, we found consistent seasonal difference in suspended Cr concentration and δ53Cr. Suspended δ53Cr is 0.1‰ higher than the unfractionated BSE in the fall (0.01–0.13‰), but indistinguishable from the BSE in the spring (−0.11‰ to 0.00‰). The suspended Cr concentration is also lower in the spring, and with higher Al-Mn-Fe concentrations. The lower suspended Cr concentration and δ53Cr in spring may be linked to increased silicate and oxide load with depleted Cr due to stronger hydrological flux. Building from our dataset, there is not a consistent correlation with climate zones in a compilation of δ53Cr and Cr concentration data from river water and weathering profiles, suggesting that climate is not a dominating factor controlling Cr isotopic behavior during weathering, suggesting that other factors (e.g., local catchment conditions and dissolved organic matter) may also be responsible for the observed river water δ53Cr variability.
Altered metabolism is one of the hallmarks of cancer cells. The best-known metabolic abnormality in cancer cells is the Warburg effect, which demonstrates an increased glycolysis even in the presence ...of oxygen. However, tumor-related metabolic abnormalities are not limited to altered balance between glucose fermentation and oxida- tive phosphorylation. Key tumor genes such as p53 and c-myc are found to be master regulators of metabolism. Metabolic enzymes such as succinate dehydrogenase, fumarate hydratase, pyruvate kinase, and isocitrate dehydrogenase mutations or expressing level alterations are all linked to tumorigenesis. In this review, we intro- duce some of the cancer-associated metabolic disorders and current understanding of their molecular tumorigenic mechanisms.
This paper focuses on achieving the low-cost coexistence of the networks in an unlicensed spectrum by making them operate on non-overlapping channels. For achieving this goal, we first give a ...universal convergence analysis framework for the unlicensed spectrum allocation algorithm. Then, a one-timescale iteration-adjustable unlicensed spectrum allocation algorithm is developed, where the step size and timescale parameter can be jointly adjusted based on the system performance requirement and signal overhead concern. After that, we derive the sufficient condition for the one-timescale algorithm. Furthermore, the upper bound of convergence error of the one-timescale spectrum allocation algorithm is obtained. Due to the multi-timescale evolution of the network states in the wireless network, we further propose a two-timescale iteration-adjustable joint frequency selection and frequency allocation algorithm, where the frequency selection iteration timescale is set according to the slow-changing statistical channel state information (CSI), whereas the frequency allocation iteration timescale is set according to the fast-changing local CSI. Then, we derive the convergence condition of two-timescale algorithms and the upper bound of the corresponding convergence error. The experimentalresults show that the small timescale adjustment parameter and large step size can help decrease the convergence error. Moreover, compared with traditional algorithms, the two-timescale policy can achieve throughput similar to traditional algorithms with very low iteration overhead.
Naturally, many aerobic organisms degrade lignin-derived aromatics through conserved intermediates including protocatechuate and catechol. Employing this microbial approach offers a potential ...solution for valorizing lignin into valuable chemicals for a potential lignocellulosic biorefinery and enabling bioeconomy. In this study, two hybrid biochemical routes combining lignin chemical depolymerization, plant metabolic engineering, and synthetic pathway reconstruction were demonstrated for valorizing lignin into value-added products. In the biochemical route 1, alkali lignin was chemically depolymerized into vanillin and syringate as major products, which were further bio-converted into cis, cis-muconic acid (ccMA) and pyrogallol, respectively, using engineered Escherichia coli strains. In the second biochemical route, the shikimate pathway of Tobacco plant was engineered to accumulate protocatechuate (PCA) as a soluble intermediate compound. The PCA extracted from the engineered Tobacco was further converted into ccMA using the engineered E. coli strain. This study reports a direct process for converting lignin into ccMA and pyrogallol as value-added chemicals, and more importantly demonstrates benign methods for valorization of polymeric lignin that is inherently heterogeneous and recalcitrant. Our approach also validates the promising combination of plant engineering with microbial chassis development for the production of value added and speciality chemicals.
Seismic fault structures are important for the detection and exploitation of hydrocarbon resources. Due to their development and popularity in the geophysical community, deep-learning-based fault ...detection methods have been proposed and achieved SOTA results. Due to the efficiency and benefits of full spatial information extraction, 3D convolutional neural networks (CNNs) are used widely to directly detect faults on seismic data volumes. However, using 3D data for training requires expensive computational resources and can be limited by hardware facilities. Although 2D CNN methods are less computationally intensive, they lead to the loss of correlation between seismic slices. To mitigate the aforementioned problems, we propose to predict a 2D fault section using multiple neighboring seismic profiles, that is, 2.5D fault detection. In CNNs, convolution layers mainly extract local information and pooling layers may disrupt the edge features in seismic data, which tend to cause fault discontinuities. To this end, we incorporate the Transformer module in U-net for feature extraction to enhance prediction continuity. To reduce the data discrepancies between synthetic and different real seismic datasets, we apply a seismic data standardization workflow to improve the prediction stability on real datasets. Netherlands F3 real data tests show that, when training on synthetic data labels, the proposed 2.5D Transformer U-net-based method predicts more subtle faults and faults with higher spatial continuity than the baseline full 3D U-net model.
This report outlines a versatile high-performance electrochemiluminescence (ECL) enzyme-linked immunosorbent assay (ELISA) platform, which combines the merits of high-quantum-yield Au nanocluster ...(AuNC) probe-based ECL technology, the efficient ECL-resonance energy-transfer (ECL-RET) strategy, and highly sensitive and specific ELISA technology. The ECL detection procedure was performed on a recyclable MnO2/AuNC-modified glassy carbon electrode interface by taking advantage of the ECL-RET between the AuNC probe and MnO2 nanomaterials (NMs) to quench the ECL intensity. The etching of MnO2 NMs by the product of ALP-based ELISA recovers the ECL signal. Notably, the ELISA process and the ECL detection procedure in this system are independent. Thus, the ECL-ELISA system can effectively avoid the influence of complex biological samples, and the ECL efficiency of the AuNC probe can be used readily. As demonstrated on TNF-α, because of the abovementioned characteristics, the ECL-ELISA platform presented an extremely wide dynamic range, with a detection limit of 2 orders lower than ELISA. Moreover, the system was also applicable for ultrahigh sensitive detection of various disease-related proteins and able to detect trace biomarkers in real serum samples. Therefore, this multifunctional ECL assay platform is versatile, facile, ultrasensitive, recyclable, and sufficiently straightforward for trace biomarker detection in complex biological samples. This approach not only enriches the foundational study of ECL devices but also greatly expands the potential application of ECL sensors in biological testing and clinical high-throughput diagnosis.
Silicate weathering is intimately linked to global climate. To investigate the controlling factors of silicate weathering rate, we collected monthly or half-monthly river water samples from ten small ...granitic watersheds in the Jiuhua Mountains. Mass balance calculation shows that agricultural activity, atmospheric input, silicate weathering, carbonate weathering and evaporite dissolution contribute 2.0%, 16.9%, 58.7%, 13.5% and 8.9% cations to the river water, respectively. The disproportionate contribution of carbonate rocks with an exposed area of <5% demonstrates the importance of trace carbonate minerals in these small granitic watersheds. The average silicate weathering and CO2 consumption rates at our sites are 7.0 t km−2 y−1 and 3.4 × 105 mol km−2 y−1, respectively.
There is no correlation between silicate weathering rates (SWR) and the suspended solid concentrations (an index of physical erosion rate), but there is a strong positive correlation between SWR and temperature, consistent with the kinetic-limited chemical weathering regime in alpine areas. A compilation of literature data from global small granitic watersheds in different climatic zones shows positive correlations between temperature, runoff and SWR. A multiple linear regression between SWR, temperature and runoff yielded an adjusted R-squared of 0.61, showing that climatic factors can account for 61% of the variation in SWR. In addition, for catchments where the elevation difference between the highest point of the headwater and sampling point (an approximate topographical parameter) exceeds 400 m, the R-squared value obtained from the temperature and SWR regression analysis is significantly increased, indicating that temperature is likely the most important factor controlling silicate weathering in the alpine region where a kinetic-limited regime dominates.
ObjectiveTo assess the efficacy and safety of intradialytic exercise for haemodialysis patients.DesignSystematic review and meta-analysis.Data sourcesDatabases, including PubMed, Embase, the Cochrane ...Library, China Biology Medicine and China National Knowledge Infrastructure, were screened from inception to March 2017.Eligibility criteriaRandomised controlled trials (RCTs) aimed at comparing the efficacy and safety of intradialytic exercise versus no exercise in adult patients on haemodialysis for at least 3 months. A minimum exercise programme period of 8 weeks.Data extractionStudy characteristics and study quality domains were reviewed. Studies were selected, and data extracted by two reviewers.Data analysisThe pooled risk ratios and mean differences (MDs) with 95% CIs for dichotomous data and continuous data were calculated, respectively.ResultsA total of 27 RCTs involving 1215 subjects were analysed. Compared with no exercise, intradialytic exercise increased dialysis adequacy (Kt/V) (MD 0.07, 95% CI 0.01 to 0.12, p=0.02) and maximum volume of oxygen that the body can use during physical exertion peak oxygen consumption (MD 4.11, 95% CI 2.94 to 5.27, p<0.0001), alleviated depression standardised mean difference (−1.16, 95% CI −1.86 to –0.45, p=0.001) and improved physical component summary-short form-36 (SF-36) level (MD 7.72, 95% CI 1.93 to 13.51, p=0.009). Also, intradialytic exercise could significantly reduce systolic blood pressure (MD −4.87, 95% CI −9.20 to –0.55, p=0.03) as well as diastolic blood pressure (MD −4.11, 95% CI −6.50 to –1.72, p=0.0007). However, intradialytic exercise could not improve mental component summary-SF-36 level (MD 3.05, 95% CI −1.47 to 7.57, p=0.19). There was no difference in the incidence of adverse events between the intradialytic exercise and control groups.ConclusionsIntradialytic exercise resulted in benefits in terms of improving haemodialysis adequacy, exercise capacity, depression and quality of life for haemodialysis.
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