Activated carbon materials have been playing a significant role in addressing the challenges posed with the ever-increasing demand for alternative clean and sustainable energy technologies. In the ...present study, a facile strategy is proposed for generating porosity in porous carbons by using carton box as the precursor and eutectic NaOH–KOH melt as the activating agent. The prepared carbon materials have a very high specific surface area up to 2731 m2 g−1 with large pore volume of 1.68 cm3 g−1, which is greater than that of only KOH was used at the same mass ratio. Electrochemical studies based on symmetric supercapacitor devices demonstrating that the NaOH–KOH melt activated porous carbon exhibits significantly improved rate capability in the range of 0.5–75 A g−1 despite of the similar specific capacitance with respect to KOH activated carbon at a low current density of 0.5 A g−1. The remarkable deviations in capacitive behavior at high current density for the NaOH–KOH melt activated porous carbon and KOH activated samples highlighting the specific surface area is not the only parameter that determines the capacitive performance especially at high charge–discharge rate.
•Activated carbons were prepared using carton box as the precursor.•Eutectic NaOH–KOH melt activated carbon shows better graphitization.•Both large specific capacitance and excellent rate capability were achieved.•The high surface area and mesoporosity is beneficial for ion adsorption and diffusion.
Alzheimer's disease (AD), the most common form of dementia, is highly prevalent in older adults. The main clinical feature is the progressive decline of memory function, which eventually leads to the ...decline of cognitive function. At present, the pathogenesis of AD is unclear. In the disease process, synaptic changes are the key. Recent studies have shown that the dysregulation of RNA methylation is related to many biological processes, including neurodevelopment and neurodegenerative diseases. N6-methyladenosine (m6A) is the most abundant modification in eukaryotic RNA. In this study, RNA m6A methylation was quantified in APP/PS1 transgenic mice, which is an AD mouse model, and C57BL/6 control mice, and data showed that m6A methylation was elevated in the cortex and the hippocampus of APP/PS1 transgenic mice. Next, the alterations of m6A RNA methylation in AD and in C57BL/6 mice were investigated using high-throughput sequencing. Genome-wide maps of m6A mRNA showed that the degrees of m6A methylation were higher in many genes and lower in others in AD mice. Interestingly, the expression of the m6A methyltransferase METTL3 was elevated and that of the m6A demethylase FTO was decreased in AD mice. The data were analyzed by gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses, and pathways that might be related to synaptic or neuron development and growth were constructed. The related pathways and genes predicted the potential roles of the differentially expressed m6A methylation RNA in AD. Collectively, our findings demonstrate that the m6A methylation of RNA promotes the development of AD.
•A general approach for fabrication of nitrogen-doped graphene sheets has been developed.•Large amount of nitrogen was incorporated into the nanocarbon frameworks.•Nitrogen-doped graphene sheets can ...be used as electrodes for supercapacitors.•The as-prepared nitrogen-doped graphene exhibits excellent capacitive performance.
In this paper, a general and efficient strategy has been developed to produce nitrogen-doped graphene sheets (NGs) based on hard and soft acids and bases (HSAB) theory. Under hydrothermal conditions, any salt with amphiprotic character have a strong tendency to hydrolysis, it is possible to provide reducing agent and nitrogen source simultaneously. It is worth noting that, NGs can be prepared under hydrothermal conditions by using some common ammonium salts with hard acid-soft base pairs as nitrogen-doping agents. The morphology, structure and composition of the as-prepared NGs were studied in detail. The results demonstrated that large amount of nitrogen was incorporated into the nanocarbon frameworks at the same time as the graphene oxide (GO) sheets were reduced. The electrochemical behavior of the synthesized NGs as supercapacitor electrodes was evaluated in a symmetric two-electrode cell configuration with 1M H2SO4 as the electrolytes. It was found that the nitrogen groups making the as-prepared NGs exhibited remarkably enhanced electrochemical performance when used as electrode materials in supercapacitors. The supercapacitor based on the NGs exhibited a high specific capacitance of 242Fg−1 at a current density of 1Ag−1, and remains a relatively high capacitance even at a high current density. This work will put forward to understand and optimize heteroatom-doped graphene in energy storage systems.
Alzheimer’s disease (AD) is the most common neurodegenerative disease characterized by excessive accumulation of the amyloid-β peptide (Aβ) in the brain, which has been considered to mediate the ...neuroinflammation process. Microglial activation is the main component of neuroimmunoregulation. In recent years, exosomes isolated from human umbilical cord mesenchymal stem cells (hucMSC-exosomes) have been demonstrated to mimic the therapeutic effects of hucMSCs in many inflammation-related diseases. In this study, exosomes from the supernatant of hucMSCs were injected into AD mouse models. We observed that hucMSC-exosomes injection could repair cognitive disfunctions and help to clear Aβ deposition in these mice. Moreover, we found that hucMSC-exosomes injection could modulate the activation of microglia in brains of the mice to alleviated neuroinflammation. The levels of pro-inflammatory cytokines in peripheral blood and brains of mice were increased and the levels of anti-inflammatory cytokines were decreased. We also treated BV2 cells with hucMSC-exosomes in culture medium. HucMSC-exosomes also had inflammatory regulating effects to alternatively activate microglia and modulate the levels of inflammatory cytokines in vitro.
To study the stratal stacking patterns and controls on coal accumulation in a lowland alluvial plain, coastal plain, and shallow-marine setting, the depositional facies, sequence stratigraphy, and ...paleogeography of the Carboniferous–Permian strata in the Anyang-Hebi (Anhe) coalfield, Henan Province, northern China were analyzed based on borehole cores. Ten facies were grouped into four facies associations, which represent alluvial plain, delta plain, delta front and prodelta, and offshore marine depositional environments. Ten sequences (S1 to S10, in ascending order) were defined on the basis of vertical facies stacking patterns. Sequences S1–S3, of Moscovian to early Asselian age, are composed mainly of offshore marine carbonate and mudstone, prodelta and delta front mudstone and sandstone, and delta plain sandstone, mudstone and coal. Sequences S4–S9, late Asselian to Wuchiapingian in age, consist of delta plain sandstone, mudstone and coal. Sequence S10, corresponding to the Changhsingian stage, is composed mainly of alluvial plain sandstone and mudstone. From S1 to S10, the Anhe coalfield experienced an environmental evolution from offshore marine, prodelta and delta front through delta plain to alluvial plain environments, an evolution from a low-accommodation to a high-accommodation setting, and a paleoclimatic change from humid to semi-arid conditions. Coal accumulation was controlled by a combination of relative sea-level fluctuation, paleoclimate and paleogeography. The cyclothemic nature of S2, including presence of parasequences, and the significant sea-level fall interpreted at the base of S4 may be related to Gondwanan ice dynamics in the late Carboniferous–early Permian. The thick coals are concentrated in the transgressive systems tracts of S2 and S4. The results of this study provide new insights into the environmental evolution of Carboniferous–Permian lowland alluvial plain, coastal plain and shallow-marine successions of the northern subtropical paleolatitudes and the controls on coal deposits in North China.
•The Anhe coalfield is preserved with Carboniferous-Permian successions.•The paleoenvironment changes from offshore marine through delta to alluvial plain.•From S1 to S10, the paleoclimate changes from humid to semi-arid condition.•The S2 and S4 are related to two episodes of glaciations of the Late Paleozoic.•The sea-level fluctuations related to Gondwanan glaciations controls coal deposits.
Abstract
To determine the heavy metal(loid)s (HMs) contamination of agricultural soil in hotbed chives hometown of Tangchang, 788 topsoil samples were collected and analyzed for their heavy ...metal(loid)s concentration. The index of geo-accumulation (I
geo
), pollution index (PI) and potential ecological risk index (EI
i
) were used to assess the degree of pollution. Correlation analysis and principal component analysis (PCA) were used to determine the sources of soil HMs. Human health risks estimated with hazard index (HI) and carcinogenic risk (CR) indices based on ingestion, inhalation and dermal exposure pathways for adults and children. The mean values of Cd, Hg, As, Pb, Cr, Cu, Ni and Zn were 0.221, 0.155, 9.76, 32.2, 91.9, 35.2, 37.1 and 108.8 mg kg
−1
, respectively, which did not exceed the threshold values of the risk screening value for soil contamination. The potential ecological risk of soil heavy metal(loid)s was low level and there was no significant human health risk. Based on PCA, Pb and Hg may originate from transportation and atmospheric deposition, Zn, Cr and Ni may originate from natural sources and industrial activities, and Cu and Cd may originate from agricultural activities. Overall, from the perspective of HMs content, the soil quality in this study area was at a clean level. This study provides a reference and a basis for formulating effective measures to prevent and control HMs enrichment in agricultural soils.
Comparison of chemical index of alteration (CIA) values and estimated land surface temperatures (LSTs) from upper Carboniferous-Permian successions in low paleolatitude North China and middle- to ...high-paleolatitude successions of Gondwana facilitates reconstruction of global climate changes during the late Paleozoic Ice Age. Four synchronous excursions between the North China and Gondwana Basins toward lower CIA and LSTs are recognized and interpreted as four cooling events, respectively. Two severe cooling events occurred around 300 Ma and 287 Ma, respectively, with large decreases in global temperatures (mostly >5 °C), while another two less-pronounced cooling events at 297.5 Ma and 295 Ma with global temperature drops of <5 °C are defined as discrete pulses superimposed on the earlier, more severe cooling interval. Overlap in the timing of decreased chemical weathering intensity in different parts of North China and glaciations in some Gondwanan Basins that coincide with stepwise decreases in pCO2 suggest that CO2-forced climate change was likely one of the most important driving factors for the continental weathering changes and the onset and demise of glaciations. Local tectonism, atmospheric and ocean circulation, and orbital parameters also played the roles in driving the glaciations and deglaciations. The continued effects from weathering of worldwide mafic rocks along with expansion of paleotropical forests are considered to be contributors to the cooling intervals along with glacial events and evolution of ecosystems during the late Pennsylvanian-Cisuralian.
•Late Pennsylvanian-Cisuralian weathering trends and temperatures are reconstructed.•Two global cooling intervals started around 300 Ma and 287 Ma, respectively.•CO2-forced climate change controlled the global continental weathering changes.•Mafic-rock weathering and paleotropical forests expansion caused cooling intervals.
The oxidation/weathering of molybdenite (MoS
) is too slow to be monitored, even under pure oxygen and high temperatures, while it proceeds rapidly through humid air. The adsorption of water ...molecules on molybdenite is necessary for the wet oxidation/weathering of molybdenite. Therefore, we employ kinetic Monte Carlo modeling to clarify the adsorption isotherm, site preferences and kinetics of water on different surfaces of molybdenite. Our results indicate that (1) the adsorption capacity and adsorption rate coefficient of H
O on the (110) surface are significantly larger than those on the (001) surface at a temperature of 0~100 °C and a relative humidity of 0~100%, suggesting that the (110) surface is the predominant surface controlling the reactivity and solubility of molybdenite in its interaction with water; (2) the kinetic Monte Carlo modeling considering the adsorption/desorption rate of H
O, dissociation/formation rate of H
O and adsorption/desorption of dissociated H indicates that the adsorption and dissociation of H
O on the (110) surface can be completed in one microsecond (ms) at 298 K and in wet conditions; (3) the adsorption and dissociation of H
O on molybdenite are not the rate-limiting steps in the wet oxidation/weathering of molybdenite; and (4) kinetic Monte Carlo modeling explains the experimental SIMS observation that H
O and OH (rather than H
/H
or H
O) occupy the surface of MoS
in a short time. This study provides new molecular-scale insights to aid in our understanding of the oxidation/weathering mechanism of molybdenite as the predominant mineral containing molybdenum in the Earth's crust.
The purpose of current retrospective study was to review the surgical methods and to evaluate the clinical efficacy of supporting plate for the treatment of vertical medial malleolus fractures on the ...basis of stable fixation of ipsilateral fibula.
This retrospective study included a total of 191 patients with vertical medial malleolus fractures. Patients enrolled were divided into simple vertical medial malleolus fractures and complex types of fractures. General demographic information and surgical information, including age, sex, surgical procedure and postoperative complications, were collected. The functional prognosis of patients was evaluated by American Orthopedic Foot and Ankle Society Ankle-Hindfoot Score (AOFAS) and Visual Analog Scale (VAS).
Among patients with simple vertical fractures, the respective incidence of internal fixation failure in screw group, buttress plate group, and screw combined buttress plate fixation group (combined fixation group) was 10/61 (16.4%),1/54 (7.4%) and 1 (1.9%), and the difference was statistically significant (P = 0.024). The incidence of abnormal fracture growth and healing in screw group, buttress plate group and combined fixation group was, respectively, 13/61 (21.3%), 6/54 (12.5%) and 2 (3.85%), with statistically significant difference (P = 0.019). In the patients with complex types of fractures, after 2 years of postoperative follow-up, the AOFAS score and VAS score of the following subgroups had good results: 91.18 ± 6.05 and 2.18 ± 1.08 in patients with joint surface collapse, and 92.50 ± 4.80 and 2.50 ± 1.29 in patients with tibial fractures, with 100% excellent and good rate.
For simple and complex vertical medial malleolus fractures, buttress plate showed excellent fixation. Despite poor wound healing and extensive soft tissue dissection with this approach, buttress plate may provide a novel insight into medial malleolar fractures, especially for extremely unstable medial malleolar fractures.
Cinobufacini (Huachansu), a Chinese medicine prepared from the skin of
Bufo bufo gargarizans
Cantor (
Bufonidae
), has potent anti-tumor activity in vitro and in vivo. However, the molecular ...mechanism of cell apoptosis induced by Bufalin remains elusive. Here, we investigated the apoptosis in Bufalin-treated human osteosarcoma MG-63 cells. The results showed that Bufalin could inhibit cell proliferation and induce apoptosis in a dose- and time-dependent manner. Further investigation revealed that a disruption of mitochondrial transmembrane potential (MMP) and an up-regulation of reactive oxygen species (ROS) in Bufalin-treated cells. By western blot analysis, we found that the up-regulation of Apaf-1, cleaved PARP, cleaved caspase-3, cleaved caspase-9, and Bax/Bcl-2, varies with different concentration of Bufalin. These protein interactions may play a pivotal role in the regulation of apoptosis. Taken together, these results overall indicate that Bufalin could be used as an effective anti-tumor agent in therapy of osteosarcoma targets the mitochondrial-dependent signaling pathway.
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