Electrocatalytic nitrogen reduction reaction (NRR) is a promising strategy for ammonia (NH3) production under ambient conditions. However, it is severely impeded by the challenging activation of the ...NN bond and the competing hydrogen evolution reaction (HER), which makes it crucial to design electrocatalysts rationally for efficient NRR. Herein, the rational design of bismuth (Bi) nanoparticles with different oxidation states embedded in carbon nanosheets (Bi@C) as efficient NRR electrocatalysts is reported. The NRR performance of Bi@C improves with the increase of Bi0/Bi3+ atomic ratios, indicating that the oxidation state of Bi plays a significant role in electrochemical ammonia synthesis. As a result, the Bi@C nanosheets annealed at 900 °C with the optimal oxidation state of Bi demonstrate the best NRR performance with a high NH3 yield rate and remarkable Faradaic efficiency of 15.10 ± 0.43% at −0.4 V versus RHE. Density functional theory calculations reveal that the effective modulation of the oxidation state of Bi can tune the p‐filling of active Bi sites and strengthen adsorption of *NNH, which boost the potential‐determining step and facilitate the electrocatalytic NRR under ambient conditions. This work may offer valuable insights into the rational material design by modulating oxidation states for efficient electrocatalysis.
An oxidation state modulation strategy is proposed to boost nitrogen reduction to ammonia. As a proof‐of‐concept, the surface oxidation of Bi species is tuned with the less occupied p orbital, which leads to stronger adsorption of *NNH and lower ΔG of the potential‐determining step. By optimizing Bi surface oxidation, superior nitrogen reduction reaction performance of Faradaic efficiency of 15.10 ± 0.43% is achieved.
Full text
Available for:
BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Electrocatalytic C‐N coupling reaction is regarded as a promising strategy for achieving clean and sustainable urea production by coreducing CO2 and nitrogen species, thus contributing to carbon ...neutrality and the artificial nitrogen cycle. However, restricted by the sluggish adsorption of reactants, competitive side reactions, and multistep reaction pathways, the electrochemical urea production suffers from a low urea yield rate and low selectivity so far. In order to comprehensively improve urea synthesis performance, it is crucial to develop highly efficient catalysts for electrochemical C‐N coupling. In this article, the catalyst‐designing strategies, C‐N coupling mechanisms, and fundamental research methods are reviewed. For the coreduction of CO2 and different nitrogen species, several prevailing reaction mechanisms are discussed. With the aim of establishing the standard research system, the fundamentals of electrocatalytic urea synthesis research are introduced. The most important catalyst‐designing strategies for boosting the electrocatalytic urea production are discussed, including heteroatom doping, vacancy engineering, crystal facet regulation, atom‐scale modulation, alloying and heterostructure construction. Finally, the challenges and perspectives are proposed for future industrial applications of electrochemical urea production by C‐N coupling.
The rational design of efficient heterogeneous electrocatalysts is crucial but still very challenging for sustainable urea production at ambient conditions by coreducing CO2 and nitrogen species. In this review article, design strategies for C‐N coupling electrocatalysts are emphasized‐for the in‐depth understanding of the structure‐activity relationship and the establishment of a systematic research framework ‐toward this emerging field.
Full text
Available for:
FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Electrocatalytic nitrogen reduction reaction (NRR) is promising for achieving clean ammonia (NH
3
) production under mild conditions but suffers from the difficult adsorption/activation of nitrogen ...molecules and the severe hydrogen evolution reaction (HER). Herein, crystalline-amorphous interfaces between crystalline Bi and amorphous MoO
x
anchored on reduced graphene oxide (RGO) (Bi-MoO
x
@RGO) are constructed for achieving the electrochemical NRR. The Bi-MoO
x
@RGO electrocatalysts show excellent NRR performance with an NH
3
yield rate of 19.93 ± 0.47 μg h
−1
mg
−1
at −0.4 V
vs.
reversible hydrogen electrode (RHE) and a faradaic efficiency of 17.17 ± 0.81% at −0.3 V
vs.
RHE. The combination of experimental results and theoretical calculations reveals that the boosted NRR performance is due to the crystalline Bi-amorphous MoO
x
interfaces which facilitate the adsorption/activation of N
2
while suppressing the competitive HER, thus achieving the simultaneous enhancement of NH
3
yield rate and the faradaic efficiency of the NRR. The utilization of the gas diffusion electrode in the flow cell further increased the NH
3
yield rate to 35.29 ± 1.08 μg h
−1
mg
−1
at −0.3 V
vs.
RHE by virtue of enhanced N
2
transportation. This work paves the way for the rational design of electrocatalysts by phase engineering and interface modulation for the efficient electrocatalytic NRR.
Crystalline Bi-amorphous MoO
x
interfaces anchored on RGO exhibit superior electrocatalytic NRR performance by enhancing the N
2
adsorption/activation while suppressing the competitive HER process.
Electrocatalytic nitrogen reduction reaction (NRR) is promising for achieving ammonia (NH3) synthesis under ambient conditions, but restricted by the lack of efficient catalysts. Herein, 3D ...hierarchical architectures of Mo2C nanosheets supported on porous carbon matrix (Mo2C@C) are rationally designed for boosting the electrocatalytic NRR. The morphology engineering endows Mo2C@C electrocatalysts with hierarchically porous architectures, which can sufficiently expose the surface-active sites and enhance the mass diffusion and electron transfer. Moreover, the composition modulation strategy can not only retain the adequate adsorption of N2, but also restrict the hydrogen evolution reaction (HER). Accordingly, Mo2C@C electrocatalysts exhibit a high NH3 yield rate of 12.55 ± 1.04 μg/h/mg at −0.20 V vs. RHE and a well-balanced Faradaic efficiency. Theoretical calculations further confirm the strong N2 adsorption/activation on the Mo2C catalyst and the NRR mechanism of the preferred distal pathway. The morphology engineering and composition modulation strategies can be extended to other materials, guiding the rational design of efficient NRR catalysts.
Display omitted
•3D hierarchically porous Mo2C@C was constructed via a salt-template method.•The hierarchically porous structures can effectively increase the surface-active sites.•Modulation of the Mo2C content can balance the competitive HER process and the N2 adsorption/activation.•DFTcalculations reveal the NRR mechanism on the Mo2C catalyst.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Display omitted
Inborn errors of immunity have been implicated in causing immune dysregulation, including allergic diseases. STAT6 is a key regulator of allergic responses.
This study sought to ...characterize a novel gain-of-function STAT6 mutation identified in a child with severe allergic manifestations.
Whole-exome and targeted gene sequencing, lymphocyte characterization, and molecular and functional analyses of mutated STAT6 were performed.
This study reports a child with a missense mutation in the DNA binding domain of STAT6 (c.1114G>A, p.E372K) who presented with severe atopic dermatitis, eosinophilia, and elevated IgE. Naive lymphocytes from the affected patient displayed increased TH2- and suppressed TH1- and TH17-cell responses. The mutation augmented both basal and cytokine-induced STAT6 phosphorylation without affecting dephosphorylation kinetics. Treatment with the Janus kinase 1/2 inhibitor ruxolitinib reversed STAT6 hyperresponsiveness to IL-4, normalized TH1 and TH17 cells, suppressed the eosinophilia, and improved the patient’s atopic dermatitis.
This study identified a novel inborn error of immunity due to a STAT6 gain-of-function mutation that gave rise to severe allergic dysregulation. Janus kinase inhibitor therapy could represent an effective targeted treatment for this disorder.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Active vibration control under a time-variant secondary path is a research priority in the field of vibration suppression. To track the varied secondary path, the mirror modified filtered-x least ...mean square (MMFxLMS) algorithm is proposed. However, due to the expensive computing cost and difficulty to adjust the modeling performance of the primary and secondary paths independently, the application of the MMFxLMS algorithm is limited. The algorithm is studied in this paper. First, the complexity is reduced by simplifying the normalization using an exponential window. The convergence of the overall modeling algorithm using different stepsizes and the influence of the background noise on the overall modeling results are analyzed, respectively. Simulation studies show that the algorithm using different stepsizes reaches a better performance than the classical MMFxLMS algorithm. To illustrate the proposed method is a promising algorithm, experiments on controlling the vibration of the piping system, which is basic cooling equipment on a ship propulsion system, are carried out. As these investigations illustrate, the proposed measures efficiently improve the performances of the MMFxLMS algorithm in convergence speed, control effect, and the property of dealing with time-varying parameters.
Full text
Available for:
NUK, OILJ, SAZU, UKNU, UL, UM, UPUK
Glioma is the most common intracranial malignant tumor. Cancer stem cells (CSCs) are resistant to chemotherapy and radiotherapy, and are closely related to cancer metastasis and recurrence. In this ...study, we aimed to explore the effect of miR-484 on glioma stemness and the underlying mechanism involved. miR-484 enhanced glioma tumor-initiating properties in vitro and in vivo. Moreover, miR-484 was shown to directly target MAP2, resulting in activation of ERK1/2 signaling and promotion of stemness in glioma. The ERK1/2 signaling facilitated the formation of a miR-484/MAP2/c-Myc positive feedback loop in glioma. High miR-484 expression predicted a poor prognosis for glioma patients, and high MAP2 expression predicted a good prognosis for glioma patients. Low miR-484 expression and high MAP2 expression was associated with the best prognosis in glioma. Our study suggests that miR-484 and MAP2 can be utilized as predictors for the clinical diagnosis and prognosis of glioma, and miR-484 and MAP2 are potential targets for the treatment of glioma.
Full text
Available for:
EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Interstitial pneumonia in connective tissue diseases (CTD-IP) featuring inflammation and fibrosis is a leading cause of death in CTD-IP patients. The related autoimmune lung injury and disturbed ...self-healing process make conventional anti-inflammatory drugs ineffective. Equipped with unique immunoregulatory and regenerative properties, mesenchymal stem cells (MSCs) may represent a promising therapeutic agent in CTD-IP. In this study, we aim to define the immunopathology involved in pulmonary exacerbation during autoimmunity and to determine the potential of MSCs in correcting these disorders.
Lung and blood specimens, bronchoalveolar lavage fluid cells collected from CTD-IP patients, and human primary lung fibroblasts (HLFs) from patients pathologically diagnosed with usual interstitial pneumonia (UIP) and healthy controls were analyzed by histology, flow cytometry and molecular biology. T cell subsets involved in the process of CTD-IP were defined, while the regulatory functions of MSCs isolated from the bone marrow of normal individuals (HBMSCs) on cytotoxic T cells and CTD-UIP HLFs were investigated in vitro.
Higher frequencies of cytotoxic T cells were observed in the lung and peripheral blood of CTD-IP patients, accompanied with a reduced regulatory T cell (Treg) level. CTD-UIP HLFs secreted proinflammatory cytokines in combination with upregulation of α-smooth muscle actin (α-SMA). The addition of HBMSCs in vitro increased Tregs concomitant with reduced cytotoxic T cells in an experimental cell model with dominant cytotoxic T cells, and promoted Tregs expansion in T cell subsets from patients with idiopathic pulmonary fibrosis (IPF). HBMSCs also significantly decreased proinflammatory chemokine/cytokine expression, and blocked α-SMA activation in CTD-UIP HLFs through a TGF-β1-mediated mechanism, which modulates excessive IL-6/STAT3 signaling leading to IP-10 expression. MSCs secreting a higher level of TGF-β1 appear to have an optimal anti-fibrotic efficacy in BLM-induced pulmonary fibrosis in mice.
Impairment of TGF-β signal transduction relevant to a persistent IL-6/STAT3 transcriptional activation contributes to reduction of Treg differentiation in CTD-IP and to myofibroblast differentiation in CTD-UIP HLFs. HBMSCs can sensitize TGF-β1 downstream signal transduction that regulates IL-6/STAT3 activation, thereby stimulating Treg expansion and facilitating anti-fibrotic IP-10 production. This may in turn block progression of lung fibrosis in autoimmunity.
Full text
Available for:
IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Human umbilical cord mesenchymal stem cells (hUC-MSCs) have shown very attractive potential in clinical applications for the treatment of various diseases. However, the data about the reproductive ...and developmental toxicity of hUC-MSCs remains insufficient. Thus, we assessed the potential effects of intravenous injection of hUC-MSCs on reproduction and development in Sprague-Dawley rats.
In the fertility and early embryonic development study, hUC-MSCs were administered at dose levels of 0, 6.0 × 10
, 8.5 × 10
, and 1.2 × 10
/kg to male and female rats during the pre-mating, mating and gestation period. In the embryo-fetal development study, the pregnant female rats received 0, 6.0 × 10
, 1.2 × 10
, and 2.4 × 10
/kg of hUC-MSCs from gestation days (GD) 6-15. Assessments made included mortality, clinical observations, body weight, food consumption, fertility parameters of male and female, litter, and fetus parameters, etc.
No hUC-MSCs-related toxicity was observed on the fertility of male and female rats, and no teratogenic effect on fetuses. hUC-MSCs at 1.2 × 10
/kg caused a mildly decrease in body weight gain of male rats, transient listlessness, tachypnea, and hematuria symptoms in pregnant female rats. Death was observed in part of the pregnant females at a dose of 2.4 × 10
/kg, which could be due to pulmonary embolism.
Based on the results of the studies, the no-observed-adverse-effect levels (NOAELs) are 8.5 × 10
/kg for fertility and early embryonic development, 1.2 × 10
/kg for maternal toxicity and 2.4 × 10
/kg for embryo-fetal development in rats intravenous injected with hUC-MSCs, which are equivalent to 8.5-fold, 12-fold, and 24-fold respectively of its clinical dosage in humans. These findings may provide a rational basis for human health risk assessment of hUC-MSCs.
The changes in the numbers, phenotypes, and subpopulations of B lymphocytes in patients with chronic graft‐versus‐host disease (cGVHD) with different response levels after mesenchymal stromal cell ...(MSC) treatment were investigated. The findings imply that MSCs might exert therapeutic effects in cGVHD patients, accompanied by alterations of naïve and memory B‐cell subsets, modulating the plasma B cell‐activating factor (BAFF) levels and BAFF receptor expression on B lymphocytes.
Although mesenchymal stromal cells (MSCs) possess immunomodulatory properties and exhibit promising efficacy against chronic graft‐versus‐host disease (cGVHD), little is known about the immune changes by which MSCs ameliorate cGVHD in vivo. Recent studies have suggested that B lymphocytes might play an important role in the pathogenesis of cGVHD. In this study, we investigated changes in the numbers, phenotypes, and subpopulations of B lymphocytes in cGVHD patients who showed a complete response (CR), partial response (PR), or no response (NR) after MSC treatment. We found that the frequencies and numbers of CD27+ memory and pre‐germinal center B lymphocytes were significantly increased in the CR and PR cGVHD patients after MSC treatment but decreased in the NR patients. A further analysis of CR/PR cGVHD patients showed that MSC treatment led to a decrease in the plasma levels of B cell‐activating factor (BAFF) and increased expression of the BAFF receptor (BAFF‐R) on peripheral B lymphocytes but no changes in plasma BAFF levels or BAFF‐R expression on B lymphocytes in NR patients. Overall, our findings imply that MSCs might exert therapeutic effects in cGVHD patients, accompanied by alteration of naïve and memory B‐cell subsets, modulating plasma BAFF levels and BAFF‐R expression on B lymphocytes.
Full text
Available for:
FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
PDF
