Isomerization Engineering of Oxygen-Enriched Carbon Quantum Dots for Efficient Electrochemical Hydrogen Peroxide Production.

Hydrogen peroxide (H2O2) has emerged as a kind of multi-functional green oxidants with extensive industrial utility. Oxidized carbon materials exhibit promises as electrocatalysts in the two-electron (2e-) oxygen reduction reaction (ORR) for H2O2 production. However, the precise identification and fabrication of active sites that selectively yield H2O2 present a serious challenge. Herein, a structural engineering strategy is employed to synthesize oxygen-doped carbon quantum dots (o-CQD) for the 2e- ORR. The surface electronic structure of the o-CQDs is systematically modulated by varying isomerization precursors, thereby demonstrating excellent electrocatalyst performance. Notably, o-CQD-3 emerges as the most promising candidate, showcasing a remarkable H2O2 selectivity of 96.2% (n = 2.07) at 0.68 V versus RHE, coupled with a low Tafel diagram of 66.95 mV dec-1. In the flow cell configuration, o-CQD-3 achieves a H2O2 productivity of 338.7 mmol gcatalyst -1 h-1, maintaining consistent production stability over an impressive 120-hour duration. Utilizing in situ technology and density functional theory calculations, it is unveil that edge sites of o-CQD-3 are facilely functionalized by C-O-C groups under alkaline ORR conditions. This isomerization engineering approach advances the forefront of sustainable catalysis and provides a profound insight into the carbon-based catalyst design for environmental-friendly chemical synthesis processes.

Engineering Built-In Electric Field Microenvironment of CQDs/g-C3N4 Heterojunction for Efficient Photocatalytic CO2 Reduction.

Graphitic carbon nitride (CN), as a nonmetallic photocatalyst, has gained considerable attention for its cost-effectiveness and environmentally friendly nature in catalyzing solar-driven CO2 conversion into valuable products. However, the photocatalytic efficiency of CO2 reduction with CN remains low, accompanied by challenges in achieving desirable product selectivity. To address these limitations, a two-step hydrothermal-calcination tandem synthesis strategy is presented, introducing carbon quantum dots (CQDs) into CN and forming ultra-thin CQD/CN nanosheets. The integration of CQDs induces a distinct work function with CN, creating a robust interface electric field after the combination. This electric field facilitates the accumulation of photoelectrons in the CQDs region, providing an abundant source of reduced electrons for the photocatalytic process. Remarkably, the CQD/CN nanosheets exhibit an average CO yield of 120 µmol g-1, showcasing an outstanding CO selectivity of 92.8%. The discovery in the work not only presents an innovative pathway for the development of high-performance photocatalysts grounded in non-metallic CN materials employing CQDs but also opens new avenues for versatile application prospects in environmental protection and sustainable cleaning energy.

Synergistic Effects of Amine Functional Groups and Enriched-Atomic-Iron Sites in Carbon Dots for Industrial-Current-Density CO2 Electroreduction.

Metal phthalocyanine molecules with Me-N4 centers have shown promise in electrocatalytic CO2 reduction (eCO2R) for CO generation. However, iron phthalocyanine (FePc) is an exception, exhibiting negligible eCO2R activity due to a higher CO2 to *COOH conversion barrier and stronger *CO binding energy. Here, amine functional groups onto atomic-Fe-rich carbon dots (Af-Fe-CDs) are introduced via a one-step solvothermal molecule fusion approach. Af-Fe-CDs feature well-defined Fe-N4 active sites and an impressive Fe loading (up to 8.5 wt%). The synergistic effect between Fe-N4 active centers and electron-donating amine functional groups in Af-Fe-CDs yielded outstanding CO2-to-CO conversion performance. At industrial-relevant current densities exceeding 400 mA cm-2 in a flow cell, Af-Fe-CDs achieved >92% selectivity, surpassing state-of-the-art CO2-to-CO electrocatalysts. The in situ electrochemical FTIR characterization combined with theoretical calculations elucidated that Fe-N4 integration with amine functional groups in Af-Fe-CDs significantly reduced energy barriers for *COOH intermediate formation and *CO desorption, enhancing eCO2R efficiency. The proposed synergistic effect offers a promising avenue for high-efficiency catalysts with elevated atomic-metal loadings.

Spire2 and Rab11a synergistically activate myosin-5b motor function.

Cellular vesicle long-distance transport along the cytoplasmic actin network has recently been uncovered in several cell systems. In metaphase mouse oocytes, the motor protein myosin-5b (Myo5b) and the actin nucleation factor Spire are recruited to the Rab11a-positive vesicle membrane, forming a ternary complex of Myo5b/Spire/Rab11a that drives the vesicle long-distance transport to the oocyte cortex. However, the mechanism underlying the intermolecular regulation of the Myo5b/Spire/Rab11a complex remains unknown. In this study, we expressed and purified Myo5b, Spire2, and Rab11a proteins, and performed ATPase activity measurements, pulldown and single-molecule motility assays. Our results demonstrate that both Spire2 and Rab11a are required to activate Myo5b motor activity under physiological ionic conditions. The GTBM fragment of Spire2 stimulates the ATPase activity of Myo5b, while Rab11a enhances this activation. This activation occurs by disrupting the head-tail interaction of Myo5b. Furthermore, at the single-molecule level, we observed that the GTBM fragment of Spire2 and Rab11a coordinate to stimulate the Myo5b motility activity. Based on our results, we propose that upon association with the vesicle membrane, Myo5b, Spire2 and Rab11a form a ternary complex, and the inhibited Myo5b is synergistically activated by Spire2 and Rab11a, thereby triggering the long-distance transport of vesicles.

Amide Covalent Bonding Engineering in Heterojunction for Efficient Solar-Driven CO2 Reduction.

Inefficient charge separation and slow interfacial reaction dynamics significantly hamper the efficiency of photocatalytic CO2 reduction. Herein, a facile EDC/NHS-assisted linking strategy was developed to enhance charge separation in heterojunction photocatalysts. Using this approach, we successfully synthesized amide-bonded carbon quantum dot-g-C3N4 (CQD-CN) heterojunction photocatalysts. The formation of amide covalent bonds between CN and CQDs in the CN-CQD facilitates efficient carrier migration, CO2 adsorption, and activation. Exploiting these advantages, the CN-CQD photocatalysts exhibit high selectivity with CO and CH4 evolution rates of 79.2 and 2.7 µmol g-1 h-1, respectively. These rates are about 1.7 and 3.6 times higher than those of CN@CQD and bulk CN, respectively. Importantly, the CN-CQD photocatalysts demonstrate exceptional stability, even after 12 h of continuous testing. The presence of the COOH* signal is identified as a crucial intermediate species in the conversion of CO2 to CO. This study presents a covalent bonding engineering strategy for developing high-performance heterojunction photocatalysts for efficient solar-driven reduction of CO2.

Morphological Characteristics of Various Cells in Esophageal Squamous Dysplasia: Extremely Wide Morphological Spectrum.

The WHO classification of esophageal tumors divides esophageal squamous intraepithelial dysplasia into high and low grades, but does not specify its morphological spectrum. Here, the morphological characteristics of various cells were investigated in esophageal squamous (high-grade) dysplasia, and a morphological spectrum and terminology for this lesion were proposed to avoid misdiagnosis. The clinicopathological data of 540 patients with esophageal squamous dysplasia were analyzed retrospectively. According to the unique cytomorphological characteristics of the lesions and the predominant cell type, the esophageal squamous dysplasia was divided into the following morphological groups: classic type (34.6%, 187/540), basaloid subtype (10.7%, 58/540), spindle-cell subtype (4.6%, 25/540), differentiated subtype (48.9%, 264/540), and verrucous subtype (1.1%, 6/540). Gender, age, and lesions location did not differ among the subtypes (P > 0.05), while Paris classification and lesions diameter significantly differed among the subtypes (P < 0.01). Classic-type cells showed severe atypia. In the basaloid subtype, the cells were small, and resembled basal cells; most of these lesions were of the 0-IIb type with small lesion diameter. In the spindle-cell subtype, the cells and nuclei were spindle-shaped or long and spindle-shaped and arranged in parallel. Differentiated-subtype showed well-to-moderately differentiated cells, and epithelial basal cells were mature. Verrucous-subtype showed well-differentiated cells, and were characterized by verrucous or papillary structures. Esophageal squamous dysplasia has extremely wide morphological spectrum. Awareness of the spectrum of morphological presentations of this lesion, specifically the basaloid subtype, spindle-cell subtype, differentiated subtype, and verrucous subtype, is important for accurate diagnosis.

Functional Group Modulation in Carbon Quantum Dots for Accelerating Photocatalytic CO2 Reduction.

This study investigates the mechanism behind the enhanced photocatalytic performance of carbon quantum dot (CQD)-induced photocatalysts. Red luminescent CQDs (R-CQDs) were synthesized using a microwave ultrafast synthesis strategy, exhibiting similar optical and structural properties but varying in surface functional group sites. Model photocatalysts were synthesized by combining R-CQDs with graphitic carbon nitride (CN) using a facile coupling technique, and the effects of different functionalized R-CQDs on CO2 reduction were investigated. This coupling technique narrowed the band gap of R1-CQDs/CN, made the conduction band potentials more negative, and made photogenerated electrons and holes less likely to recombine. These improvements greatly enhanced the deoxygenation ability of the photoinduced carriers, increased light absorption of solar energy, and raised the carrier concentration, resulting in excellent stability and remarkable CO production. R1-CQDs/CN demonstrated the highest photocatalytic activity, with CO production up to 77 µmol g-1 within 4 h, which is approximately 5.26 times higher than that of pure CN. Our results suggest that the superior photocatalytic performance of R1-CQDs/CN arises from its strong internal electric field and high Lewis acidity and alkalinity, attributed to the abundant pyrrolic-N and oxygen-containing surface groups, respectively. These findings offer a promising strategy for producing efficient and sustainable CQD-based photocatalysts to address global energy and environmental problems.

Insights into the Use of Te-O Pairs as Active Centers of Carbon Nanosheets for Efficient Electrochemical Oxygen Reduction.

Previous theoretical calculations have predicted that the incorporation of tellurium (Te) into carbon materials can significantly enhance their catalytic activity. Nevertheless, the experimental realization of efficient Te-doped carbon materials remains challenging. Here, we employed theoretical calculations to deduce the possible structure of Te-doped carbon materials. Our findings unveil that the formation of Te-O pairs in carbon materials with a relatively low oxygen coordination microenvironment can impart strong electron-donating capabilities, thereby boosting the electrocatalytic activity of oxygen reduction reaction (ORR). To verify our theoretical predictions, we synthesized Te-O pair-doped carbon materials using a tandem hydrothermal dehydration-pyrolysis strategy. This approach enabled efficient infiltration of Te into carbon materials. Our unconventional Te-O pair-doped carbon materials exhibit expanded interlayer distances and graphene-like nanosheet architectures, which provide enlarged active areas. These structural features contribute to the enhanced ORR catalytic performance of the as-prepared carbon catalyst. Our findings provide molecular-level insights into the design of various carbon-based electrocatalysts with binary-heteroatom-doped active sites.

Isolated transition metal nanoparticles anchored on N-doped carbon nanotubes as scalable bifunctional electrocatalysts for efficient Zn-air batteries.

Accelerating the sluggish anode reaction in a Zn-air battery can improve its energy efficiency, but the large-scale development of this battery is hindered by the lack of bifunctional catalysts. Herein, we designed a one-step carbonization strategy for synthesizing monodispersed Co nanoparticles supported on N-doped carbon nanotube (Co/CNT), which shows excellent bifunctional electrocatalytic performance with long-term durability for oxygen reduction reaction/oxygen evolution reaction. The formation of carbon substrates from the carbonization of nitrogenous organic molecules are benefit to capture more Co nanoparticles though strong metal-substrate interaction, then construct high-density effective active sites of the Lewis base for accelerating the electrocatalytic reaction process. To verify its superior performance, a rechargeable Zn-air battery with a Co/CNT air electrode was subsequently constructed. The battery exhibits an open-circuit voltage of 1.41 V and a specific discharge capacity of 835.2 mAh/gZn, which can be continuously charged and discharged with good cycle stability. Our study provides a new strategy for developing various practical carbon-based non-noble metallic bifunctional electrocatalysts with promising performance in electrocatalysis and batteries to achieve the target of carbon neutrality.

Overexpression of RLIP76 Required for Proliferation in Meningioma Is Associated with Recurrence.

The GTPase-activating protein RLIP76 is overexpressed in and correlates with the pathological grade of many malignant tumor cells. But the potential correlation between RLIP76 and clinical outcomes in patients with meningioma remains unknown. In this study, we examined the expression of RLIP76 in meningioma and correlated the RLIP76 expression to the patient outcome. RLIP76 expression in tumor tissues was examined with immunohistochemistry, quantitative reverse-transcription polymerase chain reaction(RT-PCR) and Western-blot. Immunohistochemistry showed an increased RLIP76 immunostaining score in anaplastic and atypical meningiomas versus classical meningiomas. Statistical analyses revealed that RLIP76 immunostaining positively correlated with immunostaining for Ki-67, a nuclear protein highly expressed in proliferating cells(r=0.29, p=0.034 by Spearman's correlation coefficient). Clinicopathological evaluation suggested that RLIP76 expression be associated with tumor grade and recurrence(P<0.05). Univariate and Cox analysis indicated that RLIP76 was an independent prognostic factor for tumor recurrence. Furthermore, the human malignant meningioma cell lines IOMM-Lee and CH157-MN stably transfected with short hairpin RNA (siRNA) targeting RLIP76 were then examined by in vitro growth assays, and apoptosis assays. RLIP76 knockdown in IOMM-Lee and CH157-MN cells inhibited cell proliferation and induced apoptosis. Western blot analysis revealed that cells underexpressing RLIP76 exhibited decreased B-cell lymphoma-2(Bcl-2) expression but increased apoptosis effector caspase-3 expression. These findings demonstrate that high RLIP76 expression is associated with a poor outcome of meningioma and may provide a new gene therapy approach for patients with malignant meningiomas.

[Image reconstruction in electrical impedance tomography based on genetic algorithm].

Image reconstruction in electrical impedance tomography (EIT) is a highly ill-posed, non-linear inverse problem. The modified Newton-Raphson (MNR) iteration algorithm is deduced from the strictest theoretic analysis. It is an optimization algorithm based on minimizing the object function. The MNR algorithm with regularization technique is usually not stable, due to the serious image reconstruction model error and measurement noise. So the reconstruction precision is not high when used in static EIT. A new static image reconstruction method for EIT based on genetic algorithm (GA-EIT) is proposed in this paper. The experimental results indicate that the performance (including stability, the precision and space resolution in reconstructing the static EIT image) of the GA-EIT algorithm is better than that of the MNR algorithm.