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1.
J Genet Genomics ; 51(9): 911-921, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-38582297

RESUMO

MicroRNAs (miRNAs) play a significant role in axon regeneration following spinal cord injury. However, the functions of numerous miRNAs in axon regeneration within the central nervous system (CNS) remain largely unexplored. Here, we elucidate the positive role of microRNA-2184 (miR-2184) in axon regeneration within zebrafish Mauthner cells (M-cells). The upregulation of miR-2184 in a single M-cell can facilitate axon regeneration, while the specific sponge-induced silencing of miR-2184 leads to impeded regeneration. We show that syt3, a downstream target of miR-2184, negatively regulates axon regeneration, and the regeneration suppression modulated by syt3 depends on its binding to Ca2+. Furthermore, pharmacological stimulation of the cAMP/PKA pathway suggests that changes in the readily releasable pool may affect axon regeneration. Our data indicate that miR-2184 promotes axon regeneration of M-cells within the CNS by modulating the downstream target syt3, providing valuable insights into potential therapeutic strategies.


Assuntos
Axônios , MicroRNAs , Regeneração Nervosa , Sinaptotagminas , Proteínas de Peixe-Zebra , Animais , Axônios/metabolismo , Axônios/fisiologia , Cálcio/metabolismo , MicroRNAs/genética , MicroRNAs/metabolismo , Traumatismos da Medula Espinal/genética , Traumatismos da Medula Espinal/metabolismo , Traumatismos da Medula Espinal/patologia , Sinaptotagminas/genética , Sinaptotagminas/metabolismo , Peixe-Zebra/genética , Proteínas de Peixe-Zebra/genética , Proteínas de Peixe-Zebra/metabolismo
2.
Ecotoxicology ; 33(3): 239-252, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38573560

RESUMO

Despite the prevalence of discharge of large volumes of heavy-metal-bearing seawater from coal-fired power plants into adjacent seas, studies on the associated ecological risks remain limited. This study continuously monitored concentrations of seven heavy metals (i.e. As, Cd, Cr, Cu, Hg, Pb, and Zn) in surface seawater near the outfall of a coal-fired power plant in Qingdao, China over three years. The results showed average concentrations of As, Cd, Cr, Cu, Hg, Pb, and Zn of 2.63, 0.33, 2.97, 4.63, 0.008, 0.85, and 25.00 µg/L, respectively. Given the lack of data on metal toxicity to local species, this study investigated species composition and biomass near discharge outfalls and constructed species sensitivity distribution (SSD) curves with biological flora characteristics. Hazardous concentrations for 5% of species (HC5) for As, Cd, Cr, Cu, Hg, Pb, and Zn derived from SSDs constructed from chronic toxicity data for native species were 3.23, 2.22, 0.06, 2.83, 0.66, 4.70, and 11.07 µg/L, respectively. This study further assessed ecological risk of heavy metals by applying the Hazard Quotient (HQ) and Joint Probability Curve (JPC) based on long-term heavy metal exposure data and chronic toxicity data for local species. The results revealed acceptable levels of ecological risk for As, Cd, Hg, and Pb, but unacceptable levels for Cr, Cu, and Zn. The order of studied heavy metals in terms of ecological risk was Cr > Cu ≈ Zn > As > Cd ≈ Pb > Hg. The results of this study can guide the assessment of ecological risk at heavy metal contaminated sites characterized by relatively low heavy metal concentrations and high discharge volumes, such as receiving waters of coal-fired power plant effluents.


Assuntos
Mercúrio , Metais Pesados , Poluentes do Solo , Monitoramento Ambiental/métodos , Cádmio , Chumbo , Metais Pesados/toxicidade , Água do Mar , Medição de Risco , Centrais Elétricas , China , Carvão Mineral , Solo , Poluentes do Solo/análise
3.
Nat Commun ; 14(1): 7518, 2023 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-37980409

RESUMO

Supported metal clusters comprising of well-tailored low-nuclearity heteroatoms have great potentials in catalysis owing to the maximized exposure of active sites and metal synergy. However, atomically precise design of these architectures is still challenging for the lack of practical approaches. Here, we report a defect-driven nanostructuring strategy through combining defect engineering of nitrogen-doped carbons and sequential metal depositions to prepare a series of Pt and Mo ensembles ranging from single atoms to sub-nanoclusters. When applied in continuous gas-phase decomposition of formic acid, the low-nuclearity ensembles with unique Pt3Mo1N3 configuration deliver high-purity hydrogen at full conversion with unexpected high activity of 0.62 molHCOOH molPt-1 s-1 and remarkable stability, significantly outperforming the previously reported catalysts. The remarkable performance is rationalized by a joint operando dual-beam Fourier transformed infrared spectroscopy and density functional theory modeling study, pointing to the Pt-Mo synergy in creating a new reaction path for consecutive HCOOH dissociations.

4.
Phys Chem Chem Phys ; 25(25): 16952-16961, 2023 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-37326588

RESUMO

Two-dimensional carbon-based materials have great potential for electrocatalysis. Herein, we screen 12 defective and doped C3N nanosheets by evaluating their CO2RR and NRR activity and selectivity vs. the HER based on density functional theory calculations. The calculation results suggest that all 12 C3Ns can enhance CO2 adsorption and activation. And PN-VC-C3N is the best electrocatalyst for the CO2RR towards HCOOH with UL = -0.17 V, which is much more positive than most of the reported values. BN-C3N and PN-C3N are also good electrocatalysts that promote the CO2RR towards HCOOH (UL = -0.38 V and -0.46 V). Moreover, we find that SiC-C3N can reduce CO2 to CH3OH, adding an alternative option to the limited catalysts available for the CO2RR to CH3OH. Furthermore, BC-VC-C3N, BC-VN-C3N, and SiC-VN-C3N are promising electrocatalysts for the HER with |ΔGH*| ≤ 0.30 eV. However, only three C3Ns of BC-VC-C3N, SiC-VN-C3N, and SiC-VC-C3N can slightly improve N2 adsorption. And none of the 12 C3Ns are found to be suitable for the electrocatalytic NRR because all the ΔeNNH* values are larger than the corresponding ΔGH* values. The high performance of C3Ns in the CO2RR stems from the altered structure and electronic properties, which result from the introduction of vacancies and doping elements into C3N. This work identifies suitable defective and doped C3Ns for excellent performance in the electrocatalytic CO2RR, which will inspire relevant experimental studies to further explore C3Ns for electrocatalysis.

5.
Chem Commun (Camb) ; 59(26): 3827-3837, 2023 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-36883229

RESUMO

Fischer-Tropsch synthesis (FTS), which provides a green route to the production of clean fuels and fine chemicals, represents some significant applications of catalytic materials and processes in the chemical industry. FTS reactions show a diversity of mechanisms, involve various catalytic materials, and offer options for continuous investigation. Cobalt-based catalysts have been widely used for Fischer-Tropsch synthesis both in academia and in industry. This mini-review will focus on relevant research achievements in cobalt-based FTS catalysts by our group in the Dalian Institute of Chemical Physics (DICP). Specific contents will include the development of Co/Co2C-based nano-catalysts (i) for the highly selective synthesis of clean fuels over Co-based catalysts supported by carbon materials and (ii) for the synthesis of linear α-alcohols and olefins over Co-Co2C-based catalysts supported by carbon materials. The direct synthesis of linear α-alcohols from syngas using a Co-Co2C/AC catalyst is highlighted. The innovative work of FTS using activated carbon (AC)-supported Co/Co2C-based nano-catalysts could bring some insight into new FTS catalyst designs.

6.
J Psychoactive Drugs ; : 1-11, 2023 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-36919533

RESUMO

Medical cannabis use among U.S. Veterans has continued to rise. However, data on cannabis use by older Veterans is generally less available. This study aims to understand the characteristics of older Veterans who enrolled in the Medical Cannabis Patient Program in Illinois and analyze their health outcomes and co-use of cannabis and opioids using longitudinal survey data. Overall, participants reported positive outcomes for pain, sleep, and emotional problems because of cannabis use in two survey periods. Approximately, 62% and 85% respondents reported no change in memory and falls, respectively, with only 3% and 1% reporting a negative outcome for the conditions in both surveys. About 20.4% of those who indicated cannabis use only in the initial survey started to co-use opioids in the follow-up survey, while 44.1% of those who indicated the use of both substances in the initial survey reported no longer using opioids in the follow-up survey. However, these changes were not statistically significant (α=0.05). The logistic regression showed that both clinical and contextual factors affected co-use. In conclusion, older U.S. Veterans may be using cannabis to alleviate their pain and other chronic conditions. More research is needed to understand the effect of cannabis use on reducing or substituting opioids.

7.
Water Res ; 226: 119245, 2022 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-36283233

RESUMO

MNBs (Micro-nano bubbles) are widely used in cleaning processes for environmental treatments, but few studies have examined the interaction of MNBs with coagulation. In this study, a novel process, i.e., MNBs-coagulation, was developed for enhanced drinking water treatment. The humic acid (HA) removal efficiency was used to evaluate the effectiveness of MNBs-coagulation for drinking water treatment. The hydrolysis component ratio of polymeric aluminum chloride (PACl) with and without MNBs, the complexation strength of HA and PACl, and flocculent functional group characterization were used to analyze the mechanism of the MNBs-coagulation process to enhance drinking water treatment. The results of a Jar test showed that the MNBs-coagulation process could improve the removal efficiency of HA (up to a 27.9% increase in DOC removal). In continuous-flow experiments to remove HA, MNBs-coagulation can increase the removal efficiency of UV254 by about 26.5% and with no significant change in turbidity. These results are attributed to the inherent hydroxyl radical generating properties of MNBs, the forced hydrolysis of PACl by MNBs to increase the Alc percentage, and the ability of MNBs to increase the complexation strength of HA with PACl. At the same time, the MNBs-coagulation process has a strong anti-interference ability, almost no interference from anions and cations such as Cl-, SO42- and Ca2+, and has a good performance in natural surface water. In summary, MNBs-coagulation has strong potential for practical applications to enhance the efficiency of drinking water treatment.


Assuntos
Água Potável , Purificação da Água , Floculação , Hidróxido de Alumínio , Purificação da Água/métodos , Substâncias Húmicas/análise , Cloreto de Alumínio
8.
ACS Appl Mater Interfaces ; 7(3): 2088-96, 2015 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-25549108

RESUMO

Coordination polymers with large surface areas and uniform but tunable cavities have attracted extensive attention because of their unique properties and potential applications in numerous fields. The introduction of noble metal into coordination polymers, which may enhance or display new behaviors beyond their parent counterparts, presents great challenges in maintaining the fragile coordination structures and meeting the compatibility. Here, cyano-bridged coordination polymers are robust and show very nice compatibilities with a series of noble metals, such as Pd, Pt, Au, Ag. Those noble elements partially take the place of the transition metal ions under room temperature (for Au and Ag) or a mild hydrothermal environment (for Pd and Pt) without damaging the framework. By using this universal simple synthetic procedure, we prepared a series of noble metal containing metal hexacyanoferrate (MHCF) with various morphologies and structures, including Pd/Pt/Ag/Au-MnHCF, Pd/Pt/Ag/Au-CoHCF, and Pd/Pt/Ag/Au-NiHCF. Among them, Pd-MnHCF demonstrates the control of morphologies by adjusting operational details, and notably, it shows very unique, enhanced catalytic performance, reflecting the superiority of cyano-connected positive-valent Pd as a single-atom catalyst.

9.
Inorg Chem ; 53(17): 9073-9, 2014 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-25139392

RESUMO

Noble metal nanocatalysts with remarkable catalytic properties have attracted much attention; however, the high cost of these materials limits their industrial applications. Here, we design and prepare Co@SiO2 nanorattles as a mixture of hcp-Co and fcc-Co phases as a substitute. The nanorattles exhibit both superior catalytic activity and high stability for the reduction of p-nitrophenol. The reduction rate nearly follows pseudo-first-order kinetics, and the reaction rate constant is as high as 0.815 min(-1) and is maintained at 0.565 min(-1) even after storing for one month, which is higher than that reported for noble metal nanocatalysts. Such an excellent property can be attributed to the novel two-phase composition and rattle-type structure.

10.
ACS Nano ; 8(3): 2951-8, 2014 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-24568359

RESUMO

Optical second harmonic generation (SHG) is known as a sensitive probe to the crystalline symmetry of few-layer transition metal dichalcogenides (TMDs). Layer-number dependent and polarization resolved SHG have been observed for the special case of Bernal stacked few-layer TMDs, but it remains largely unexplored for structures deviated from this ideal stacking order. Here we report on the SHG from homo- and heterostructural TMD bilayers formed by artificial stacking with an arbitrary stacking angle. The SHG from the twisted bilayers is a coherent superposition of the SH fields from the individual layers, with a phase difference depending on the stacking angle. Such an interference effect is insensitive to the constituent layered materials and thus applicable to hetero-stacked bilayers. A proof-of-concept demonstration of using the SHG to probe the domain boundary and crystal polarity of mirror twins formed in chemically grown TMDs is also presented. We show here that the SHG is an efficient, sensitive, and nondestructive characterization for the stacking orientation, crystal polarity, and domain boundary of van der Waals heterostructures made of noncentrosymmetric layered materials.

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