Cobalt-Mediated Defect Engineering Endows High Reversible Amorphous VS4 Anode for Advanced Sodium-Ion Storage.

Metal sulfides are promising anode materials for sodium-ion batteries (SIBs) due to their structural diversity and high theoretical capacity, but the severe capacity decay and inferior rate capability caused by poor structural stability and sluggish kinetics impede their practical applications. Herein, a cobalt-doped amorphous VS4 wrapped by reduced graphene oxide (i.e., Co0.5-VS4/rGO) is developed through a Co-induced defect engineering strategy to boost the kinetics performances. The as-prepared Co0.5-VS4/rGO demonstrates excellent rate capacities over 10 A g-1 and superior cycling stability at 5 A g-1 over 1600 cycles, which is attributed to the defects formed by Co doping, the formed amorphous structure and the robust rGO substrate. The great features of Co0.5-VS4/rGO anode are further confirmed in sodium-ion capacitors when the active carbon cathode is used. Additionally, the relationships between metal doping, the derived defects, the amorphous structure, and the sodium storage of VS4 are uncovered. This work provides deep insights into preparing amorphous functional materials and also probes the potential applications of metal sulfide-based electrode materials for advanced batteries.

Oxygen Vacancy and Interface Effect Adjusted Hollow Dodecahedrons for Efficient Oxygen Evolution Reaction.

Metal-organic frameworks (MOFs) with special morphologies provide the geometric morphology and composition basis for the construction of platforms with excellent catalytic activity. In this work, cobalt-cerium composite oxide hollow dodecahedrons (Co/Cex-COHDs) with controllable morphology and tunable composition are successfully prepared via a high-temperature pyrolysis strategy using Co/Ce-MOFs as self-sacrificial templates. The construction of the hollow structure can expose a larger surface area to provide abundant active sites and pores to facilitate the diffusion of substances. The formation and optimization of phase interface between Co3O4 and CeO2 regulate the electronic structure of the catalytic site and form a fast channel favorable to electron transport, thereby enhancing the electrocatalytic oxygen evolution activity. Based on the above advantages, the optimized Co/Ce0.2-COHDs obtained an enhanced oxygen evolution reaction (OER) performance.

Unraveling the Intercorrelation Between Micro/Mesopores and K Migration Behavior in Hard Carbon.

Pore-structure design with increased ion-diffusion ability is usually regarded as an effective strategy to improve K-storage performance in hard carbon (HC). However, the relationship between porous structure and K+ migration behavior remains unclear and requires further exploration. Herein, a series of chemically activated hard carbon spheres (denoted as AHCSs) with controllable micro/mesopores structure are successfully synthesized to explore intercorrelation between micro/mesopores and K migration behavior. The experimental results indicate AHCSs have two different K+ storage ways, that is, adsorption behavior at high potential region and intercalation process at low potential region. These behaviors are closely related to the pores structure evolution: the micropores afford extra active sites for efficient K-ions adsorption, and therefore positive correlation between micropores and adsorption-contributed capacity is confirmed; the mesopores permit more K-ions intercalation/deintercalation by offering adequate pathways, and as a result positive correlations between mesopores and intercalation-contributed capacity as well as initial Coulombic efficiency are revealed. All these together contribute to achieving excellent reversible capacity, and exceptional rate capability with an ultra-long cycle lifespan in PIBs, and simultaneously exhibit a high energy density as well as considerable cycling stability for potassium-ion full cells. These results promote a fundamental understanding of K+ migration behaviors in hard carbon.

Interconnected 3D carbon network with enhanced reaction kinetics and architecture stability for advanced potassium-ion hybrid capacitors.

Due to their high energy/power densities and ultralong cycle lifespan, potassium-ion hybrid capacitors (PIHCs) have attracted increasing research interest for large-scale energy storage systems. However, the kinetics mismatch between the battery-type anodes and capacitor-type cathodes severely hampers the further development of PIHCs. Herein, the kinetics-enhanced N-doped amorphous porous carbon with an interconnected three-dimensional (3D) network (marked as NPC) is reported. The existence of an amorphous configuration can provide numerous storage potassium sites, while the interconnected 3D network contributes to electron transfer, thus improving the reversible capacity and reaction kinetics of NPC. The expanded carbon interlayer spacing, well-established porous structure and plentiful active sites induced by N-doping greatly boost the structural stability and further increase kinetics. Benefiting from these structure merits, the NPC electrode delivers a high capacity (257.7 mA h g-1 at 0.5 A g-1), an excellent rate capability (199.5 mA h g-1 at 2 A g-1), and an extraordinary cycling stability over 3000 cycles at 2 A g-1. Moreover, coupling with activated carbon (AC) cathode and NPC anode, the assembled PIHCs exhibit ultra-large energy/ultra-high power density (177.3 W h kg-1 and 19348.3 W kg-1) with a long cycling life (81.6% capacity retention after 3000 cycles).

Zero Lithium Miscibility Gap Enables High-Rate Equimolar Li(Mn,Fe)PO4 Solid Solution.

Forming olivine-structured Li(Mn,Fe)PO4 solid solution is theoretically a feasible way to improve the energy density of the solid solutions for lithium ion batteries. However, the Jahn-Teller active Mn3+ in the solid solution restricts their energy density and rate performance. Here, as demonstrated by operando X-ray diffraction, we show that equimolar LiMn0.5Fe0.5PO4 solid solution nanocrystals undergo a single-phase transition during the whole (de)lithiation process, with a feature of zero lithium miscibility gap, which endows the nanocrystals with excellent electrochemical properties. Specifically, the energy density of LiMn0.5Fe0.5PO4 reaches 625 Wh kg-1, which is 16% higher than that of LiFePO4. Moreover, the high-performance LiMn0.5Fe0.5PO4 nanocrystals are prepared by a microwave-assisted hydrothermal synthesis in pure water.

Recent progress in electrochemical performance of carbon-based anodes for potassium-ion batteries based on first principles calculations.

Carbonaceous materials and the composite materials of transition metals compounds in carbon matrix were widely used as anode for potassium-ion batteries (PIBs). During the research of these anode materials, first-principles calculations based on adsorption energy, density of states (DOSs) as well as diffusion energy barriers was regarded as an effectively approach to investigate their potassium storage mechanism. The underlying reasons for the improvement of electrochemical performance could be well illustrated via the corresponding calculations. Moreover, first-principles calculations also played a vital role to predict the material properties of electrodes before conducting experimental analysis. Hence, this review is to analyze in-depth the effect mechanism of K-adsorption energy, DOSs as well as diffusion energy barrier and so on for electrochemical performance of carbon-based anode materials. We summarized the corresponding research progress, the challenges of first principles calculations in PIBs, and proposed the corresponding strategies along with future perspectives for further development of carbon-based anode materials. This work not only can provide theoretical guidance for the development of anode materials with excellent physical and chemical properties, but also have reference significance for other energy storage systems.

Rapamycin Induces an eNOS (Endothelial Nitric Oxide Synthase) Dependent Increase in Brain Collateral Perfusion in Wistar and Spontaneously Hypertensive Rats.

BACKGROUND AND PURPOSE: Rapamycin is a clinically approved mammalian target of rapamycin inhibitor that has been shown to be neuroprotective in animal models of stroke. However, the mechanism of rapamycin-induced neuroprotection is still being explored. Our aims were to determine if rapamycin improved leptomeningeal collateral perfusion, to determine if this is through eNOS (endothelial nitric oxide synthase)-mediated vessel dilation and to determine if rapamycin increases immediate postreperfusion blood flow. METHODS: Wistar and spontaneously hypertensive rats (≈14 weeks old, n=22 and n=15, respectively) were subjected to ischemia by middle cerebral artery occlusion (90 and 120 minutes, respectively) with or without treatment with rapamycin at 30-minute poststroke. Changes in middle cerebral artery and collateral perfusion territories were measured by dual-site laser Doppler. Reactivity to rapamycin was studied using isolated and pressurized leptomeningeal anastomoses. Brain injury was measured histologically or with triphenyltetrazolium chloride staining. RESULTS: In Wistar rats, rapamycin increased collateral perfusion (43±17%), increased reperfusion cerebral blood flow (16±8%) and significantly reduced infarct volume (35±6 versus 63±8 mm3, P<0.05). Rapamycin dilated leptomeningeal anastomoses by 80±9%, which was abolished by nitric oxide synthase inhibition. In spontaneously hypertensive rats, rapamycin increased collateral perfusion by 32±25%, reperfusion cerebral blood flow by 44±16%, without reducing acute infarct volume 2 hours postreperfusion. Reperfusion cerebral blood flow was a stronger predictor of brain damage than collateral perfusion in both Wistar and spontaneously hypertensive rats. CONCLUSIONS: Rapamycin increased collateral perfusion and reperfusion cerebral blood flow in both Wistar and comorbid spontaneously hypertensive rats that appeared to be mediated by enhancing eNOS activation. These findings suggest that rapamycin may be an effective acute therapy for increasing collateral flow and as an adjunct therapy to thrombolysis or thrombectomy to improve reperfusion blood flow.

miR-212 as potential biomarker suppresses the proliferation of gastric cancer via targeting SOX4.

BACKGROUND: Circulating microRNAs that post-transcriptionally regulate gene expressions have been reported as promising biomarkers in cancer monitoring. This study was to identify the potential role of circulating miR-212 in gastric cancer and whether it could serve as a novel biomarker for gastric cancer. METHODS: We detected the serum levels of miR-212 in 100 health people and 110 gastric cancer patients and analyzed the relationships of the serum level of miR-212 with gastric cancer. We detected the expression of miR-212 in human gastric mucosal epithelial cell line (GES-1) and human gastric cancer cell lines (NCI-N87 and SNU-16) using qRT-PCR. Then, we detected the role of 5-aza-deoxycytidine on the epigenetic regulation of miR-212 in human gastric cancer cell lines. Furthermore, luciferase reporter assay was used to detect binding activity of miR-212 on SOX4 mRNA, and their functions on the cell proliferation and apoptosis. RESULTS: The expression of miR-212 was higher in health people than that in gastric cancer patients, higher in gastric mucosal epithelial cell line than that in gastric cancer cells. miR-212 can be a circulating biomarker and an independent prognostic factor of gastric cancer. Moreover, miR-212 can directly regulate the 3'UTR of SOX4 mRNA to suppress p53 and Bax, resulting gastric cancer cells proliferation inhibition and apoptosis induction. CONCLUSION: Our study demonstrated that miR-212 was epigenetically downregulated in gastric cancer, and resulting low level of miR-212 can be a potential circulating biomarker and poor prognosis predicator of gastric cancer.

Inhibition of PAI (Plasminogen Activator Inhibitor)-1 Improves Brain Collateral Perfusion and Injury After Acute Ischemic Stroke in Aged Hypertensive Rats.

Background and Purpose- Aging and hypertension, comorbidities prevalent in the stroke population, are associated with poor collateral status and worsened stroke outcome. However, underlying mechanisms by which these conditions affect stroke outcome are not clear. We studied the role of PAI (plasminogen activator inhibitor)-1 that is increased in aging and hypertension on brain and vascular expression of inflammatory factors and perfusion that may contribute to worse stroke outcomes. Methods- Aged (≈50 weeks) and young (≈18 weeks) spontaneously hypertensive rats (SHR) were subjected to ischemia by middle cerebral artery occlusion (2 hours) and reperfusion (2 hours) with or without treatment with the PAI-1 inhibitor TM5441. Changes in middle cerebral artery and collateral perfusion territories were measured by multisite laser Doppler. Reactivity to TM5441 was studied using isolated and pressurized leptomeningeal anastomotic arterioles. Brain injury was determined by 2,3,5-triphenyltetrazolium staining and quantitative immunohistochemistry of amyloid-ß-42, PAI-1, and hemoglobin. Circulating inflammatory factors were measured by ELISA. Results- Changes in cerebral blood flow during middle cerebral artery occlusion were similar between groups, with both having poor collateral perfusion and incomplete reperfusion. However, aged SHR had greater brain injury versus young (41±2 versus 23±2%, P<0.05) as well as increased brain deposition of amyloid-ß-42 and circulating oxLDL (oxidized low-density lipoprotein). Erythrocyte aggregation and hemorrhage within the injured brain was observed in 50% of aged but no young SHR, with increased circulating PAI-1 in this subgroup of aged SHR (16±3 versus 6±2 ng/mL, P<0.05). PAI-1 inhibition with TM5441 improved brain injury but did not affect hemorrhage. TM5441 increased collateral perfusion by 38±7% and dilated leptomeningeal anastomotic arterioles by 44±10%, which was abolished by nitric oxide synthase inhibition. Conclusions- Increased injury in aged SHR seemed to be related to poor collateral perfusion, hemorrhagic transformation, increased amyloid-ß-42, and oxidative stress. PAI-1 inhibition reduced infarction in both groups of SHR that possibly due, in part, to increased collateral perfusion.

Implications for understanding ischemic stroke as a sexually dimorphic disease: the role of pial collateral circulations.

We investigated structural and functional differences in primary and pial collateral circulations in adult normotensive male and female Wistar rats. Male ( n = 10) and female ( n = 7) rats were subjected to middle cerebral artery (MCA) occlusion and changes in relative cerebral blood flow in MCA and pial collateral territories were measured by multisite laser-Doppler flowmetry. Rats were then transcardially perfused with a mixture of carbon black and latex, perfusion fixed, and imaged to compare primary and pial collateral structure between male ( n = 4) and female ( n = 3) rats, including lumen diameters and number. To study pial collateral function, leptomeningeal anastomoses (LMAs) were isolated and pressurized from male ( n = 7) and female ( n = 6) rats. Myogenic tone and reactivity to pressure, vascular function to pharmacological activator, or inhibitor of ion channels was measured and compared. There was no difference between relative cerebral blood flow in both MCA and pial collateral territories during occlusion and reperfusion between groups. Compared with male LMAs, female LMAs had similar myogenic tone (24.0 ± 7.3% vs. 16.0 ± 3.7%, P > 0.05) and reactivity to increased pressure and similar vascular responses to vasoconstrictive and vasodilatory stimuli. Additionally, compared with female LMAs, male LMAs had similar numbers (21 ± 1 vs. 20 ± 2, P > 0.05) and diameters (30.5 ± 2.0 vs. 26.2 ± 0.6 µm, P > 0.05), and no sex difference was detected in the diameter of arterial segments of circle of Willis. Together, our data establish no sex difference of cerebral collateral structure or function, suggesting that the reduced severity of stroke outcome in female rats is not likely due to differences in the cerebral collateral circulation. NEW & NOTEWORTHY Our work compared the function of leptomeningeal anastomoses between male and female adult normotensive rats with no sex difference found. We also confirmed no sex difference in primary and pial collateral structure in Wistar rats. Our findings suggest that the reduced severity of stroke in premenopausal women and reproductively intact female rodents is not likely due to improved primary and pial collateral circulations.

[100]-Oriented LiFePO4 Nanoflakes toward High Rate Li-Ion Battery Cathode.

[100] is believed to be a tough diffusion direction for Li(+) in LiFePO4, leading to the belief that the rate performance of [100]-oriented LiFePO4 is poor. Here we report the fabrication of 12 nm-thick [100]-oriented LiFePO4 nanoflakes by a simple one-pot solvothermal method. The nanoflakes exhibit unexpectedly excellent electrochemical performance, in stark contrast to what was previously believed. Such an exceptional result is attributed to a decreased thermodynamic transformation barrier height (Δµb) associated with increased active population.

Interlayer coupling in two-dimensional titanium carbide MXenes.

Success in the exfoliation of the stacked T-functionalized titanium carbide MXenes Tin+1CnT2 (T = OH, O, and F) would potentially extend their application scope, which requires an understanding of the nature of interlayer coupling. Here, we report for the first time the intrinsic interlayer coupling in pristine MXenes on the basis of first-principles calculations by taking long-range interaction into account. It is demonstrated that the functional terminations (OH, O, and F) weaken the interlayer coupling as compared with the bare counterparts, whereas the coupling is significantly stronger than van der Waals bonding as specified by the fact that the binding energies of stacked Tin+1CnT2 are 2-6 times those of well-known graphite and MoS2 with weak interlayer coupling. With binding energies in the range of 1-3.3 J m(-2), the successful exfoliation of stacked Tin+1CnT2 into monolayers invariably requires further weakening of the interlayer coupling.

Vibrational properties of Ti3C2 and Ti3C2T2 (T = O, F, OH) monosheets by first-principles calculations: a comparative study.

We present a comparative study on the static and dynamical properties of bare Ti3C2 and T-terminated Ti3C2T2 (T = O, F, OH) monosheets using density functional theory calculations. First, the crystal structures are optimized to be of trigonal configurations (P3[combining macron]m1), which are thermodynamically and dynamically stable. It is demonstrated that the terminations modulate the crystal structures through valence electron density redistribution of the atoms, particularly surface Ti (Ti2) in the monosheets. Second, lattice dynamical properties including phonon dispersion and partial density of states (PDOS) are investigated. Phonon PDOS analysis shows a clear collaborative feature in the vibrations, reflecting the covalent nature of corresponding bonds in the monosheets. In the bare Ti3C2 monosheet, there is a phonon band gap between 400 and 500 cm(-1), while it disappears in Ti3C2O2 and Ti3C2(OH)2 as the vibrations associated with the terminal atoms (O and OH) bridge the gap. Third, both Raman (Eg and A1g) and infrared-active (Eu and A2u) vibrational modes are predicted and conclusively assigned. A comparative study indicates that the terminal atoms remarkably influence the vibrational frequencies. Generally, the terminal atoms weaken the vibrations in which surface Ti atoms are involved while strengthening the out-of-plane vibration of C atoms. Temperature-dependent micro Raman measurements agree with the theoretical prediction if the complexity in the experimentally obtained lamellae for the Raman study is taken into account.

Covalency-Dependent Vibrational Dynamics in Two-Dimensional Titanium Carbides.

Structure and vibrational dynamics of T-terminated titanium carbide monosheets Ti2CT2 (T = O, F, OH) are studied by means of first-principles calculations to understand their inherent relation. Terminations modulate the crystal structures through the redistribution of valence electron density among the atoms in the monosheets, particularly Ti atoms. Phonon partial density of states analysis shows a clear feature of collaborative vibration, which reflects the covalent nature of bonds in the monosheets. Two metrics of covalency and cophonicity proposed very recently are adopted to quantitatively correlate the vibrational properties with the electrostructural characteristics of the system. A remarkable positive correlation between the covalency and vibrational dynamics specified as Raman shifts and IR wavenumbers is found. The bond-specific covalency metrics depend on not only the identity of terminations but also the thickness of the two-dimensional titanium carbides. For example, in the case of Ti3C2T2 with increased thickness, red shift in Raman shifts and IR wavenumbers occurs as a result of the decrease in covalency.

Adolescent mental health interventions: a narrative review of the positive effects of physical activity and implementation strategies.

Introduction: The psychological well-being of adolescents is a global concern due to increasing societal pressures and mental health issues. Physical activity is known to enhance physical health and has potential benefits for mental health, including reducing symptoms of anxiety and depression, boosting self-esteem, and improving social skills. This narrative review explores how physical activity can serve as an intervention to help adolescents manage psychological stress and prevent mental health issues. Methods: An extensive literature search was conducted using databases such as PubMed, PsycINFO, Web of Science, and Scopus. Keywords included "adolescent mental health," "physical activity," "psychological intervention," "types of exercise," "anxiety," "depression," "self-esteem," "social skills," and "emotional regulation." Studies were included based on relevance, peer-reviewed status, and involvement of adolescent populations. Data were extracted and analyzed qualitatively, focusing on the psychological impacts of different types of physical activity. Sixty one articles were eventually included. Results and conclusion: The review identified multiple studies highlighting the positive effects of various physical activities on adolescent mental health. Aerobic exercises were found to improve mood and cognitive function, strength training reduced depressive symptoms and increased self-efficacy, team sports enhanced social skills and a sense of community, and mind-body practices like yoga and tai chi improved stress management and emotional regulation. The findings suggest that physical activity can play a significant role in promoting adolescent mental health. Implementation strategies in school and community settings, including integrating physical activity into school curricula, offering diverse activity options, training professional instructors, encouraging family and community involvement, and regular monitoring and evaluation, are recommended. Future research should address limitations such as sample diversity and long-term effects. This narrative review underscores the importance of physical activity in enhancing adolescent mental health. Effective implementation strategies and multi-sector collaboration are essential for maximizing the benefits of physical activity interventions.

Enabling Ultrastable Co-Free Li-Rich Oxides via TbF3 Treatment.

Co-free Li-rich Mn-based cathode materials (Co-free LRMOs) have become one of the most promising cathode materials in lithium-ion batteries for the next generation due to their low cost, high capacity, and environmental friendliness. Under high voltage, redox reactions involving anions can easily lead to various issues, including oxygen release, dissolution of transition metal elements (TMs), and structural collapse in these materials. The absence of the Co element further exacerbates this issue. Here, a simple one-step solid-phase reaction strategy is proposed to achieve nanoscale dual modification of the Co-free LRMOs with F and Tb doping. The dual modification has a relatively small impact on the cell parameters and Li+ diffusion ability of the LRMOs, leading to no significant improvement in its rate performance. The modified LRMOs only exhibited discharge capacities of 220.7, 200.1, 140.0, 115.5, and 90.9 mAh·g-1 at 0.1, 0.2, 1.0, 2.0, and 5.0 C, respectively. However, the modified Co-free LRMOs exhibit extremely strong structural stability and retain 95.1% of the initial capacity after 300 cycles, so far, the highest capacity retention rates among all Ni/Mn-based Li-rich materials. Mechanism studies have shown that the enhancement in structural stability of the Co-free LRMOs is attributed to the increased concentration of oxygen vacancies and Ni3+ ions through F doping. Furthermore, Tb doping not only hinders the release of O2 but also enhances the Li+ migration and electronic conductivity coefficient of the LRMOs.

Time-varying effect in older patients with early-stage breast cancer: a model considering the competing risks based on a time scale.

Background: Patients with early-stage breast cancer may have a higher risk of dying from other diseases, making a competing risks model more appropriate. Considering subdistribution hazard ratio, which is used often, limited to model assumptions and clinical interpretation, we aimed to quantify the effects of prognostic factors by an absolute indicator, the difference in restricted mean time lost (RMTL), which is more intuitive. Additionally, prognostic factors of breast cancer may have dynamic effects (time-varying effects) in long-term follow-up. However, existing competing risks regression models only provide a static view of covariate effects, leading to a distorted assessment of the prognostic factor. Methods: To address this issue, we proposed a dynamic effect RMTL regression that can explore the between-group cumulative difference in mean life lost over a period of time and obtain the real-time effect by the speed of accumulation, as well as personalized predictions on a time scale. Results: A simulation validated the accuracy of the coefficient estimates in the proposed regression. Applying this model to an older early-stage breast cancer cohort, it was found that 1) the protective effects of positive estrogen receptor and chemotherapy decreased over time; 2) the protective effect of breast-conserving surgery increased over time; and 3) the deleterious effects of stage T2, stage N2, and histologic grade II cancer increased over time. Moreover, from the view of prediction, the mean C-index in external validation reached 0.78. Conclusion: Dynamic effect RMTL regression can analyze both dynamic cumulative effects and real-time effects of covariates, providing a more comprehensive prognosis and better prediction when competing risks exist.

Facilitating Rapid Na+ Storage through MoWSe/C Heterostructure Construction and Synergistic Electrolyte Matching Strategy.

The realization of sodium-ion devices with high-power density and long-cycle capability is challenging due to the difficulties of carrier diffusion and electrode fragmentation in transition metal selenide anodes. Herein, a Mo/W-based metal-organic framework is constructed by a one-step method through rational selection, after which MoWSe/C heterostructures with large angles are synthesized by a facile selenization/carbonization strategy. Through physical characterization and theoretical calculations, the synthesized MoWSe/C electrode delivers obvious structural advantages and excellent electrochemical performance in an ethylene glycol dimethyl ether electrolyte. Furthermore, the electrochemical vehicle mechanism of ions in the electrolyte is systematically revealed through comparative analyses. Resultantly, ether-based electrolytes advantageously construct stable solid electrolyte interfaces and avoid electrolyte decomposition. Based on the above benefits, the Na half-cell assembled with MoWSe/C electrodes demonstrated excellent rate capability and a high specific capacity of 347.3 mA h g-1 even after cycling 2000 cycles at 10 A g-1. Meanwhile, the constructed sodium-ion capacitor maintains ∼80% capacity retention after 11,000 ultralong cycles at a high-power density of 3800 W kg-1. The findings can broaden the mechanistic understanding of conversion anodes in different electrolytes and provide a reference for the structural design of anodes with high capacity, fast kinetics, and long-cycle stability.

Halide-mediated endogenous ZnO domain-confined etching strategy: Realizing superior potassium storage in carbon anode.

Coupling sites of nitrogen-dopants and intrinsic carbon defects (N/DC) are highly attractive to improve potassium-storage capacity and cycling stability, yet it is hard to effectively construct them. Herein, a novel strategy is proposed to establish abundant N/DC sites in N-doped carbon (ZIF8/NaBr-1-900) by pyrolyzing the mixture of metal-organic framework (ZIF8)/sodium bromide (NaBr). Systematic investigations disclose that the introduced NaBr can promote the full conversion of Zn-N4 moieties into zinc oxide (ZnO) via a "bait and switch" mechanism. Such formed endogenous ZnO can etch the carbon matrix of the confined domains around the N dopants during pyrolysis process, and meanwhile the released N-atoms from Zn-N4 moieties can largely form edge-N. As such, these N/DC coupling sites enable the resultant carbon to have a more significant capacitive behavior related to fast K-ion migration and high structural stability, leading to 255.3 mAh/g at 2 A/g with a prolonged cycle lifespan over 2000 cycles. Moreover, the assembled K-full battery presents a high energy density of 171.2 Wh kg-1 and excellent cyclability over 5000 cycles. This NaBr-mediated endogenous ZnO domain-confined etching strategy provides a new insight into the exploration of advanced carbon anode.

[Effect of 5-aza-2'-deoxycytidine on growth and methylation of RUNX3 gene in human pancreatic cancer cell line MiaPaca2].

OBJECTIVE: To investigate the effect of demethylating agent 5-aza-2'-deoxycytidine (5-Aza-CdR) on the growth of human pancreatic cancer cell line MiaPaca2 and the expression and methylation of tumor suppressor gene RUNX3. METHODS: Human pancreatic cancer cell line MiaPaca2 cells were treated with different concentrations of 5-Aza-CdR. Morphological changes of MiaPaca2 cells were observed by light microscopy. The activity of cell proliferation was analyzed by MTT assay. The changes of RUNX3 mRNA expression were detected by semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR). Changes of RUNX3 gene methylation was detected by methylation-specific polymerase chain reaction. RESULTS: MiaPaca2 cells were treated with 2.5, 5, 10 and 20 µmo1/L 5-Aza-CdR, respectively. The inhibition rates of MiaPaca2 cells treated for 24 h were (9.17 ± 2.15)%, (10.75 ± 2.04)%, (12.57 ± 1.64)% and (18.70 ± 1.51)%, respectively. The inhibition rates were (14.94 ± 1.68)%, (18.60 ± 1.57)%, (22.84 ± 1.58)% and (33.24 ± 1.53)%, respectively, after 48 h treatment; (21.46 ± 1.60)%, (28.62 ± 1.72)%, (35.14 ± 1.64)% and (45.06 ± 1.47)%, respectively, after 72 h treatment; and (26.35 ± 1.71)%, (34.48 ± 1.69)%, (40.05 ± 1.60)% and (49.99 ± 1.61)%, respectively, after 96 h treatment. The differences between inhibition rates of each experimental and control groups (0.00 ± 0.00)% were statistically significant (P < 0.05). At the same time, the inhibition rates of different concentration groups showed significant differences (P < 0.05). At 48 h, 72 h and 96 h, the inhibition rates of each pair concentration groups showed significant differences (P < 0.05). 5-Aza- CdR inhibited the growth of MiaPaca2 cells, and the higher the concentration, the stronger the inhibition after 24 h. 5-Aza-CdR also reversed the methylation status of RUNX3 gene, and restored the expression of RUNX3 mRNA with a dose-effect relationship. CONCLUSIONS: The methylation of RUNX3 gene is significantly related with the occurrence and development of pancreatic cancer, and abnormal methylation of RUNX3 gene may contribute to the loss of RUNX3 mRNA expression. 5-Aza-CdR may effectively cause reversion of RUNX3 methylation, and treatment with 5-Aza-CdR can reactivate the gene expression and inhibit the cell growth. This may provide a new way for diagnosis and treatment of pancreatic cancer.