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Electrochemical oxygen reduction reaction (ORR) and carbon dioxide reduction reaction (CO2RR) are greatly significant in renewable energy-related devices and carbon-neutral closed cycle, while the development of robust and highly efficient electrocatalysts has remained challenges. Herein, a hybrid electrocatalyst, featuring axial N-coordinated Fe single atom sites on hierarchically N, P-codoped porous carbon support and Fe nanoclusters as electron reservoir (FeNCs/FeSAs-NPC), is fabricated via in situ thermal transformation of the precursor of a supramolecular polymer initiated by intermolecular hydrogen bonds co-assembly. The FeNCs/FeSAs-NPC catalyst manifests superior oxygen reduction activity with a half-wave potential of 0.91 V in alkaline solution, as well as high CO2 to CO Faraday efficiency (FE) of surpassing 90% in a wide potential window from -0.40 to -0.85 V, along with excellent electrochemical durability. Theoretical calculations indicate that the electron reservoir effect of Fe nanoclusters can trigger the electron redistribution of the atomic Fe moieties, facilitating the activation of O2 and CO2 molecules, lowering the energy barriers for rate-determining step, and thus contributing to the accelerated ORR and CO2RR kinetics. This work offers an effective design of electron coupling catalysts that have advanced single atoms coexisting with nanoclusters for efficient ORR and CO2RR.
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The hydrazine oxidation-assisted H2 evolution method promises low-input and input-free hydrogen production. However, developing high-performance catalysts for hydrazine oxidation (HzOR) and hydrogen evolution (HER) is challenging. Here, we introduce a bifunctional electrocatalyst α-MoC/N-C/RuNSA, merging ruthenium (Ru) nanoclusters (NCs) and single atoms (SA) into cubic α-MoC nanoparticles-decorated N-doped carbon (α-MoC/N-C) nanowires, through electrodeposition. The composite showcases exceptional activity for both HzOR and HER, requiring -80â mV and -9â mV respectively to reach 10â mA cm-2. Theoretical and experimental insights confirm the importance of two Ru species for bifunctionality: NCs enhance the conductivity, and its coexistence with SA balances the H ad/desorption for HER and facilitates the initial dehydrogenation during the HzOR. In the overall hydrazine splitting (OHzS) system, α-MoC/N-C/RuNSA excels as both anode and cathode materials, achieving 10â mA cm-2 at just 64â mV. The zinc hydrazine (Zn-Hz) battery assembled with α-MoC/N-C/RuNSA cathode and Zn foil anode can exhibit 97.3 % energy efficiency, as well as temporary separation of hydrogen gas during the discharge process. Therefore, integrating Zn-Hz with OHzS system enables self-powered H2 evolution, even in hydrazine sewage. Overall, the amalgamation of NCs with SA achieves diverse catalytic activities for yielding multifold hydrogen gas through advanced cell-integrated-electrolyzer system.
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CO plays a crucial role as an intermediate in electrochemical CO2 conversion to generate multicarbon (C2+) products. However, optimizing the coverage of the CO intermediate (*CO) to improve the selectivity of C2+ products remains a great challenge. Here, we designed a hierarchically structured double hollow spherical nanoreactor featuring atomically dispersed nickel (Ni) atoms as the core and copper (Cu) nanoparticles as the shell, which can greatly improve the catalytic activity and selectivity for C2+ compounds. Within this configuration, CO generated at the active Ni sites on the inner layer accumulates in the cavity before spilling over neighboring Cu sites on the outer layer, thus enhancing CO dimerization within the cavity. Notably, this setup achieves a sustained faradaic efficiency of 74.4% for C2+ production, with partial current densities reaching 337.4 mA cm-2. In situ Raman spectroscopy and finite-element method (FEM) simulations demonstrate that the designed local CO generator can effectively increase the local CO concentration and restrict CO evolution, ultimately boosting C-C coupling. The hierarchically ordered architectural design represents a promising solution for achieving highly selective C2+ compound production in the electroreduction of CO2.
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Phase transformation offers an alternative strategy for the synthesis of nanomaterials with unconventional phases, allowing us to further explore their unique properties and promising applications. Herein, we first observed the amorphization of Pt nanoparticles on the RuO2 surface by in situ scanning transmission electron microscopy. Density functional theory calculations demonstrate the low energy barrier and thermodynamic driving force for Pt atoms transferring from the Pt cluster to the RuO2 surface to form amorphous Pt. Remarkably, the as-synthesized amorphous Pt/RuO2 exhibits 14.2 times enhanced mass activity compared to commercial RuO2 catalysts for the oxygen evolution reaction (OER). Water electrolyzer with amorphous Pt/RuO2 achieves 1.0 A cm-2 at 1.70 V and remains stable at 200 mA cm-2 for over 80 h. The amorphous Pt layer not only optimized the *O binding but also enhanced the antioxidation ability of amorphous Pt/RuO2, thereby boosting the activity and stability for the OER.
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Integrating multiple functional components into vertically stacked heterostructures offers a prospective approach to manipulating the physicochemical properties of materials. The synthesis of vertically stacked heterogeneous noble metal oxides remains a challenge. Herein, we report a surface segregation approach to create vertically stacked amorphous Ir/Ru/Ir oxide nanosheets (NSs). Cross-sectional high-angle annular darkfield scanning transmission electron microscopy images demonstrate a three-layer heterostructure in the amorphous Ir/Ru/Ir oxide NSs, with IrOx layers located on the upper and lower surfaces, and a layer of RuOx sandwiched between the two IrOx layers. The vertically stacked heterostructure is a result of the diffusion of Ir atoms from the amorphous IrRuOx solid solution to the surface. The obtained A-Ir/Ru/Ir oxide NSs display an ultralow overpotential of 191 mV at 10 mA cm-2 toward acid oxygen evolution reaction and demonstrate excellent performance in a proton exchange membrane water electrolyzer, which requires only 1.63 V to achieve 1 A cm-2 at 60 °C, with virtually no activity decay observed after a 1300 h test.
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In China, there has been a persistent upward trend in the incidence and mortality rates of colorectal cancer (CRC), with CRC ranking second in incidence and fifth in mortality among all malignant tumors. Although circular RNAs (circRNAs) have been implicated in the progression of various cancers, their specific role in CRC progression remains largely unexplored. The objective of this study was to elucidate the role and underlying mechanisms of circXRN2 in CRC. Differential expression of circXRN2 was identified through whole transcriptome sequencing. The expression levels of circXRN2 and miR-149-5p were quantified in CRC tissues, corresponding adjacent normal tissues, and CRC cell lines using quantitative reverse transcription-polymerase chain reaction (qRT-PCR). The stability of circXRN2 was confirmed through RNase R and actinomycin D experiments. The binding interaction between circXRN2 and miR-149-5p was validated through RNA pull-down, RNA immunoprecipitation, and dual-luciferase assays. The biological functions of circXRN2 were assessed through a battery of in vitro experiments, including the CCK-8 assay, EdU assay, scratch assay, Transwell assay, and flow cytometry assay. Additionally, in vivo experiments involving a tumor transplantation model and a liver-lung metastasis model were conducted. The influence of circXRN2 on the expression of epithelial-mesenchymal transition (EMT)-related genes was determined via Western blotting analysis. In CRC tissues and cells, there was an upregulation in the expression levels of both circXRN2 and ENC1, while miR-149-5p exhibited a downregulation in its expression. The overexpression of circXRN2 was found to enhance tumor proliferation and metastasis, as evidenced by results from both in vitro and in vivo experiments. Functionally, circXRN2 exerted its antitumor effect by suppressing cell proliferation, migration, and invasion while also promoting apoptosis. Mechanistically, the dysregulated expression of circXRN2 had an impact on the expression of proteins within the EMT signaling pathway. Our results demonstrated that circXRN2 promoted the proliferation and metastasis of CRC cells through the miR-149-5p/ENC1/EMT axis, suggesting that circXRN2 might serve as a potential therapeutic target and novel biomarker in the progression of CRC.
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Neoplasias Colorretais , Neoplasias Hepáticas , Neoplasias Pulmonares , MicroRNAs , Humanos , MicroRNAs/metabolismo , Neoplasias Colorretais/patologia , Linhagem Celular , Neoplasias Pulmonares/genética , Neoplasias Hepáticas/genética , Transição Epitelial-Mesenquimal/genética , Proliferação de Células/genética , Linhagem Celular Tumoral , Regulação Neoplásica da Expressão Gênica , Transativadores/metabolismoRESUMO
Cation exchange (CE) in metal oxides under mild conditions remains an imperative yet challenging goal to tailor their composition and enable practical applications. Herein, we first develop an amorphization-induced strategy to achieve room-temperature CE for universally synthesizing single-atom doped In2O3 nanosheets (NSs). Density functional theory (DFT) calculations elucidate that the abundant coordination-unsaturated sites present in a-In2O3 NSs are instrumental in surmounting the energy barriers of CE reactions. Empirically, a-In2O3 NSs as the host materials successfully undergo exchange with unary cations (Cu2+, Co2+, Mn2+, Ni2+), binary cations (Co2+Mn2+, Co2+Ni2+, Mn2+Ni2+), and ternary cations (Co2+Mn2+Ni2+). Impressively, high-loading single-atom doped (over 10 atom %) In2O3 NSs were obtained. Additionally, Cu/a-In2O3 NSs exhibit an excellent ethanol yield (798.7 µmol g-1 h-1) with a high selectivity of 99.5% for the CO2 photoreduction. This work offers a new approach to induce CE reactions in metal oxides under mild conditions and constructs scalable single-atom doped catalysts for critical applications.
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Water electrolysis for H2 production is restricted by the sluggish oxygen evolution reaction (OER). Using the thermodynamically more favorable hydrazine oxidation reaction (HzOR) to replace OER has attracted ever-growing attention. Herein, we report a twisted NiCoP nanowire array immobilized with Ru single atoms (Ru1 -NiCoP) as superior bifunctional electrocatalyst toward both HzOR and hydrogen evolution reaction (HER), realizing an ultralow working potential of -60â mV and overpotential of 32â mV for a current density of 10â mA cm-2 , respectively. Inspiringly, two-electrode electrolyzer based on overall hydrazine splitting (OHzS) demonstrates outstanding activity with a record-high current density of 522â mA cm-2 at cell voltage of 0.3â V. DFT calculations elucidate the cooperative Ni(Co)-Ru-P sites in Ru1 -NiCoP optimize H* adsorption, and enhance adsorption of *N2 H2 to significantly lower the energy barrier for hydrazine dehydrogenation. Moreover, a self-powered H2 production system utilizing OHzS device driven by direct hydrazine fuel cell (DHzFC) achieve a satisfactory rate of 24.0â mol h-1 m-2 .
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Transition metal oxides with high theoretical capacities are promising anode materials for lithium-ion batteries (LIBs). However, the sluggish reaction kinetics remain a bottleneck for fast-charging applications due to its slow Li+ migration rate. Herein, a strategy is reported of significantly reducing the Li+ diffusion barrier of amorphous vanadium oxide by constructing a specific ratio of the VO local polyhedron configuration in amorphous nanosheets. The optimized amorphous vanadium oxide nanosheets with a ratio ≈1:4 for octahedron sites (Oh ) to pyramidal sites (C4v ) revealed by Raman spectroscopy and X-ray absorption spectroscopy (XAS) demonstrate the highest rate capability (356.7 mA h g-1 at 10.0 A g-1 ) and long-term cycling life (455.6 mA h g-1 at 2.0 A g-1 over 1200 cycles). Density functional theory (DFT)calculations further verify that the local structure (Oh :C4v = 1:4) intrinsically changes the degree of orbital hybridization between V and O atoms and contributes to a higher intensity of electron occupied states near the Fermi level, thus resulting in a low Li+ diffusion barrier for favorable Li+ transport kinetics. Moreover, the amorphous vanadium oxide nanosheets possess a reversible VO vibration mode and volume expansion rate close to 0.3%, as determined through in situ Raman and in situ transmission electron microscopy.
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BACKGROUND: Hepatic colon carcinoma invading the duodenum is not common in clinical practice. Surgical treatment of colonic hepatic cancer that invades the duodenum is difficult, and the surgical risk is high. AIM: To discuss the efficacy and safety of duodenum-jejunum Roux-en-Y anastomosis for the treatment of hepatic colon carcinoma invading the duodenum. METHODS: From 2016 to 2020, 11 patients from Panzhihua Central Hospital diagnosed with hepatic colon carcinoma were enrolled in this study. Clinical and therapeutic effects and prognostic indicators were retrospectively analyzed to determine the efficacy and safety of our surgical procedures. All patients underwent radical resection of right colon cancer combined with duodenum-jejunum Roux-en-Y anastomosis. RESULTS: The median tumor size was 65 mm (r50-90). Major complications (Clavien-DindoI-II) occurred in 3 patients (27.3%); the average length of hospital stay was 18.09 ± 4.21 d; and only 1 patient (9.1%) was readmitted during the 1st mo after the surgery. The 30-d mortality rate was 0%. After a median follow-up of 41 m (r7-58), the disease-free survival at 1, 2, and 3 years was 90.9%, 90.9% and 75.8%, respectively; the overall survival at 1, 2, and 3 years was 90.9%. CONCLUSION: In selected patients, radical resection of right colon cancer combined with duodenum-jejunum Roux-en-Y anastomosis is clinically effective, and the complications are manageable. The surgical procedure also has an acceptable morbidity rate and mid-term survival.
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The purpose of this study was to compare the effect of robotic thyroid lobectomy via Bilateral Axlio-Breast Approach (BABA) and endoscopic thyroid lobectomy on the voice function. A total of 125 patients with thyroid cancer from March 2021 to July 2022 were divided into the robotic thyroid lobectomy group and the endoscopic thyroid lobectomy group. Acoustic index and voice handicap index (VHI-10) were compared between the 2 groups before and after (1 week, 1 month, 3 month) the surgery. In the robotic group, VHI-10 score was not significantly different before and after the surgery. In the endoscopic group, VHI-10 score after the surgery was significantly higher than that before the surgery. In the endoscopic group, the fundamental frequency (F0) declined significantly 1 week and 1 month after the surgery compared with that before the surgery. One week after surgery, F0 in the endoscopic group was (197.91â ±â 24.15) Hz, which was significantly lower than that (206.77â ±â 20.13) Hz in the robotic group. In the robotic group, there was no obvious decline in F0 and MPT in each follow-up period after surgery compared with those before surgery. In the endoscopic group, MPT declined significantly 1 week after the surgery compared with that before surgery. One week after surgery, MPT in the endoscopic group was (13.02â ±â 9.28) s, which was significantly lower than that (17.55â ±â 9.25) s in the robotic groups. There were no significant differences in Shimmer, Jitter, DSI and NHR during all postoperative follow-up periods compared with those before surgery in both groups. The voice function of robotic thyroid lobectomy via BABA is superior to endoscopic thyroid lobectomy.
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Procedimentos Cirúrgicos Robóticos , Robótica , Neoplasias da Glândula Tireoide , Humanos , Glândula Tireoide , Procedimentos Cirúrgicos Robóticos/efeitos adversos , Mama , Tireoidectomia/efeitos adversos , Neoplasias da Glândula Tireoide/cirurgiaRESUMO
BACKGROUND: It is very rare to suffer from colorectal adenocarcinoma and abdominal tuberculosis simultaneously. Even in a country such as China, where tuberculosis is still endemic, its diagnosis and treatment are challenging. This article describes in detail a case of rectal cancer complicated by abdominal tuberculosis and its pathological features. CASE SUMMARY: We outline the case of a 71-year-old female who was admitted with intermittent blood in the stool over the past year. The patient was diagnosed with low rectal cancer and received neoadjuvant therapy. The patient then returned to the hospital for surgery, but diffusely distributed nodules were found during laparoscopic exploration. The diagnosis of rectal cancer with extensive metastasis was considered during the operation. There was no opportunity for radical surgery. Thus, nodules were taken for pathological examination, and the abdomen was closed. The histopathological diagnosis was tuberculous granuloma, and the patient was treated with standardized anti-tuberculosis drugs in a specialized hospital. Later, the patient again came to our hospital and underwent abdominoperineal resection. She was discharged 10 d after the operation in good clinical condition. CONCLUSION: We aim to emphasize the importance of preoperative and postoperative pathological examination in diagnosis and treatment.
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Selective photoreduction of carbon dioxide (CO2 ) into carbon-neutral fuels such as methane (CH4 ) is extremely desirable but remains a challenge since sluggish multiple proton-electron coupling transfer and various C1 intermediates are involved. Herein, a synergistic function between single Pd atoms (Pd1 ) and Pd nanoparticles (PdNPs ) on graphitic carbon nitride (C3 N4 ) for photocatalytic CO2 methanation is presented. The catalyst achieves a high selectivity of 97.8% for CH4 production with a yield of 20.3 µmol gcat. -1 h-1 in pure water. Mechanistic studies revealed that Pd1 sites activated CO2 , while PdNPs sites boosted water (H2 O) dissociation for increased H* coverage. The H* produced by PdNPs migrate to the Pd1 sites to promote multiple proton-electron coupling transfer via hydrogen spillover. Moreover, the adjacent Pd1 and PdNPs effectively stabilized intermediates such as *CHO, thereby favoring the pathway for CH4 production. This work provides a new perspective into the development of selective photocatalytic CO2 conversion through the artful design of synergistic catalytic sites.
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The controllable synthesis of stable single-metal site catalysts with an expected coordination environment for high catalytic activity and selectivity is still challenging. Here, we propose a cation-exchange strategy for precise production of an edge-rich sulfur (S) and nitrogen (N) dual-decorated single-metal (M) site catalysts (M = Cu, Pt, Pd, etc.) library. Our strategy relies on the anionic frameworks of sulfides and N-rich polymer shell to generate abundant S and N defects during high-temperature annealing, further facilitating the stabilization of exchanged metal species with atomic dispersion and excellent accessibility. This process was traced by in situ transmission electron microscopy, during which no metal aggregates were observed. Both experiments and theoretical results reveal the precisely obtained S, N dual-decorated Cu sites exhibit a high activity and low reaction energy barrier in catalytic hydroxylation of benzene at room temperature. These findings provide a route to controllably produce stable single-metal site catalysts and an engineering approach for regulating the central metal to improve catalytic performance.
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Noble metal nanomaterials have been widely used as catalysts. Common techniques for the synthesis of noble metal often result in crystalline nanostructures. The synthesis of amorphous noble metal nanostructures remains a substantial challenge. We present a general route for preparing dozens of different amorphous noble metal nanosheets with thickness less than 10 nm by directly annealing the mixture of metal acetylacetonate and alkali salts. Tuning atom arrangement of the noble metals enables to optimize their catalytic properties. Amorphous Ir nanosheets exhibit a superior performance for oxygen evolution reaction under acidic media, achieving 2.5-fold, 17.6-fold improvement in mass activity (at 1.53 V vs. reversible hydrogen electrode) over crystalline Ir nanosheets and commercial IrO2 catalyst, respectively. In situ X-ray absorption fine structure spectra indicate the valance state of Ir increased to less than + 4 during the oxygen evolution reaction process and recover to its initial state after the reaction.
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To investigate the effect of down-regulation of VEGF (vascular endothelial growth factor) and HPV18 E6/E7 by hairpin RNA (shRNA) on cell proliferation, apoptosis, migration, invasion, and adhesion abilities of cervical carcinoma cells, recombinant plasmids including pS-E6 shRNA, pS-E7 shRNA, and pS-VEGF shRNA were constructed and transfected into HeLa cells. The levels of E6 mRNA, E7 mRNA, or VEGF mRNA were significantly reduced after transfection of pS-E6 shRNA (76.0%), pS-E7 shRNA (74.4%), and pS-VEGF shRNA (46.7%). VEGF expression was down-regulated by pS-E6 shRNA (55.1%) and pS-E7 shRNA (46.6%). The apoptosis of HeLa cells was increased, and the proliferation, invasion, and adhesion abilities were decreased significantly. For in vivo study, cancer cells that stably expressed the plasmids were cultured. Cells were transplanted subcutaneously into nude mice to establish xenograft tumor model. Finally, expression of E6 shRNA, E7 shRNA, and VEGF shRNA in cancer cells led to inhibition of the growth of xenograft. Hence, RNA interference could effectively suppress the expression of HPV18 E6/E7 and VEGF in human cervical cancer cells. This suppression attenuates malignant biological behavior of human cervical cancer cells. RNA interference of HPV E6/E7 or VEGF expression implies an effective anti-cervical cancer strategy.