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1.
J Am Chem Soc ; 146(23): 15887-15896, 2024 Jun 12.
Article in English | MEDLINE | ID: mdl-38825776

ABSTRACT

Oxide thin films grown on metal surfaces have wide applications in catalysis and beyond owing to their unique surface structures compared to their bulk counterparts. Despite extensive studies, the atomic structures of copper surface oxides on Cu(111), commonly referred to as "44" and "29", have remained elusive. In this work, we demonstrated an approach for the structural determination of oxide surfaces using element-specific scanning tunneling microscopy (STM) imaging enhanced by functionalized tips. This approach enabled us to resolve the atomic structures of "44" and "29" surface oxides, which were further corroborated by noncontact atomic force microscopy (nc-AFM) measurements and Monte Carlo (MC) simulations. The stoichiometry of the "44" and "29" frameworks was identified as Cu23O16 and Cu16O11, respectively. Contrary to the conventional hypothesis, we observed ordered Cu vacancies within the "44" structure manifesting as peanut-shaped cavities in the hexagonal lattice. Similarly, a combination of Cu and O vacancies within the "29" structure leads to bean-shaped cavities within the pentagonal lattice. Our study has thus resolved the decades-long controversy on the atomic structures of "44" and "29" surface oxides, advancing our understanding of copper oxidation processes and introducing a robust framework for the analysis of complex oxide surfaces.

2.
Pharmacol Res ; 203: 107172, 2024 May.
Article in English | MEDLINE | ID: mdl-38583685

ABSTRACT

Although anti-TNF antibodies are extensively used to treat Crohn's disease (CD), a significant proportion of patients, up to 40%, exhibit an inadequate response to this therapy. Our objective was to identify potential targets that could improve the effectiveness of anti-TNF therapy in CD. Through the integration and analysis of transcriptomic data from various CD databases, we found that the expression of AQP9 was significantly increased in anti-TNF therapy-resistant specimens. The response to anti-TNF therapy in the CD mouse model was significantly enhanced by specifically inhibiting AQP9. Further experiments found that the blockade of AQP9, which is dominantly expressed in macrophages, decreased inflamed macrophage functions and cytokine expression. Mechanistic studies revealed that AQP9 transported glycerol into macrophages, where it was metabolized to LPA, which was further metabolized to LPA, resulting in the activation of the LPAR2 receptor and downstream hippo pathway, finally promoting the expression of cytokines, especially IL23 and IL1ß⊡ Taken together, the expansion of AQP9+ macrophages is associated with resistance to anti-TNF therapy in Crohn's disease. These findings indicated that AQP9 could be a potential target for enhancing anti-TNF therapy in Crohn's disease.


Subject(s)
Aquaporins , Crohn Disease , Hippo Signaling Pathway , Lysophospholipids , Macrophages , Animals , Humans , Male , Mice , Aquaporins/metabolism , Aquaporins/genetics , Aquaporins/antagonists & inhibitors , Crohn Disease/drug therapy , Crohn Disease/metabolism , Cytokines/metabolism , Hippo Signaling Pathway/drug effects , Lysophospholipids/metabolism , Macrophages/metabolism , Macrophages/drug effects , Mice, Inbred C57BL , Protein Serine-Threonine Kinases/antagonists & inhibitors , Protein Serine-Threonine Kinases/metabolism , Receptors, Lysophosphatidic Acid/antagonists & inhibitors , Receptors, Lysophosphatidic Acid/metabolism , Signal Transduction/drug effects , Tumor Necrosis Factor Inhibitors/therapeutic use , Tumor Necrosis Factor Inhibitors/pharmacology , Tumor Necrosis Factor-alpha/antagonists & inhibitors , Tumor Necrosis Factor-alpha/metabolism
3.
Angew Chem Int Ed Engl ; 63(36): e202409793, 2024 Sep 02.
Article in English | MEDLINE | ID: mdl-38923266

ABSTRACT

Due to the challenge of cleaving O-O bonds at single Co sites, mononuclear Co complexes typically show poor selectivity for the four-electron (4e-) oxygen reduction reaction (ORR). Herein, we report on selective 4e- ORR catalyzed by a Co porphyrin with a hanged ZnII ion. Inspired by Cu/Zn-superoxide dismutase, we designed and synthesized 1-CoZn with a hanging ZnII at the second sphere of a Co porphyrin. Complex 1-CoZn is much more effective than its Zn-lacking analogues to catalyze the 4e- ORR in neutral aqueous solutions, giving an electron number of 3.91 per O2 reduction. With spectroscopic studies, the hanging ZnII was demonstrated to be able to facilitate the electron transfer from CoII to O2, through an electronic "pull effect", to give CoIII-superoxo. Theoretical studies further suggested that this "pull effect" plays crucial roles in assisting O-O bond cleavage. This work is significant to present a new strategy of hanging a ZnII to improve O2 activation and O-O bond cleavage.

4.
Angew Chem Int Ed Engl ; 63(7): e202313034, 2024 Feb 12.
Article in English | MEDLINE | ID: mdl-38097503

ABSTRACT

Oxygen reduction reaction (ORR) is of critical significance in the advancement of fuel cells and zinc-air batteries. The iron-nitrogen (Fe-Nx ) sites exhibited exceptional reactivity towards ORR. However, the task of designing and controlling the local structure of Fe species for high ORR activity and stability remains a challenge. Herein, we have achieved successful immobilization of Fe species onto the highly curved surface of S, N co-doped carbonaceous nanosprings (denoted as FeNS/Fe3 C@CNS). The induction of this twisted configuration within FeNS/Fe3 C@CNS arose from the assembly of chiral templates. For electrocatalytic ORR tests, FeNS/Fe3 C@CNS exhibits a half-wave potential (E1/2 ) of 0.91 V in alkaline medium and a E1/2 of 0.78 V in acidic medium. The Fe single atoms and Fe3 C nanoparticles are coexistent and play as active centers within FeNS/Fe3 C@CNS. The highly curved surface, coupled with S substitution in the coordination layer, served to reduce the energy barrier for ORR, thereby enhancing the intrinsic catalytic activity of the Fe single-atom sites. We also assembled a wearable flexible Zn-air battery using FeNS/Fe3 C@CNS as electrocatalysts. This work provides new insights into the construction of highly curved surfaces within carbon materials, offering high electrocatalytic efficacy and remarkable performance for flexible energy conversion devices.

5.
J Am Chem Soc ; 145(9): 5353-5362, 2023 Mar 08.
Article in English | MEDLINE | ID: mdl-36853085

ABSTRACT

Photocatalysis provides an eco-friendly route for the hydrogenation of aromatic carbonyls to O-free aromatics, which is an important refining process in the chemical industry that is generally carried out under high pressure of hydrogen at elevated temperatures. However, aromatic carbonyls are often only partially hydrogenated to alcohols, which readily desorbs and are hardly further deoxygenated under ambient conditions. Here, we show that by constructing an oxide surface over the Pd cocatalyst supported on graphitic carbon nitride, an alternative hydrogenation path of aromatic carbonyls becomes available via a step-wise acetalization and hydrogenation, thus allowing efficient and selective production of O-free aromatics. The PdO surface allows for optimum adsorption of reactants and intermediates and rapid abstraction of hydrogen from the alcohol donor, favoring fast acetalization of the carbonyls and their consecutive hydrogenation to O-free hydrocarbons. The photocatalytic hydrogenation of benzaldehyde into toluene shows a high selectivity of >90% and a quantum efficiency of ∼10.2% under 410 nm irradiation. By adding trace amounts of HCl to the reaction solution, the PdO surface remains stable and active for long-term operation at high concentrations, offering perspective for practical applications.

6.
Nano Lett ; 22(17): 7203-7211, 2022 09 14.
Article in English | MEDLINE | ID: mdl-36000894

ABSTRACT

Carbon dots (C-Dots), with unique properties from tunable photoluminescence to biocompatibility, show wide applications in biotechnology, optoelectronic device and catalysis. Chiral C-Dots are expected to have strongly chirality-dependent biological and catalytic properties. For chiral C-Dots, a clear structure and quantitative structure-property relationship need to be clarified. Here, chiral C-Dots were fabricated by electrooxidation polymerization from serine enantiomers. The oxidized serine has a reversed chiral configuration to serine, which leads to the chiral C-Dots possessing inverse handedness compared with their raw materials. Electron circular dichroism spectrum, together with other diverse characterization techniques and theoretical calculations, confirmed that these chiral C-Dots (2-7 nm) have a well-defined primary structure of polycyclic dipeptide and possess a spatial structure with a c-axis of hexagonal symmetry and two cyclic dipeptides as the spatial structural unit. These chiral C-Dots also show enantioselective catalytic activity on DOPA enantiomers oxidation.


Subject(s)
Carbon , Serine , Carbon/chemistry , Catalysis , Circular Dichroism , Stereoisomerism
7.
Angew Chem Int Ed Engl ; 62(39): e202308670, 2023 Sep 25.
Article in English | MEDLINE | ID: mdl-37551119

ABSTRACT

Electrochemical water splitting is a promising approach for producing sustainable and clean hydrogen. Typically, high valence state sites are favorable for oxidation evolution reaction (OER), while low valence states can facilitate hydrogen evolution reaction (HER). However, here we proposed a high valence state of Co3+ in Ni9.5 Co0.5 -S-FeOx hybrid as the favorable center for efficient and stable HER, while structural analogues with low chemical states showed much worse performance. As a result, the Ni9.5 Co0.5 -S-FeOx catalyst could drive alkaline HER with an ultra-low overpotential of 22 mV for 10 mA cm-2 , and 175 mV for 1000 mA cm-2 at the industrial temperature of 60 °C, with an excellent stability over 300 h. Moreover, this material could work for both OER and HER, with a low cell voltage being 1.730 V to achieve 1000 mA cm-2 for overall water splitting at 60 °C. X-ray absorption spectroscopy (XAS) clearly identified the high valence Co3+ sites, while in situ XAS during HER and theoretical calculations revealed the favorable electron capture at Co3+ and suitable H adsorption/desorption energy around Co3+ , which could accelerate the HER. The understanding of high valence states to drive reductive reactions may pave the way for the rational design of energy-related catalysts.

8.
J Am Chem Soc ; 144(47): 21596-21605, 2022 11 30.
Article in English | MEDLINE | ID: mdl-36383110

ABSTRACT

On-surface synthesis is a powerful methodology for the fabrication of low-dimensional functional materials. The precursor molecules usually anchor on different metal surfaces via similar configurations. The activation energies are therefore solely determined by the chemical activity of the respective metal surfaces. Here, we studied the influence of the detailed adsorption configuration on the activation energy on different metal surfaces. We systematically studied the desulfonylation homocoupling for a molecular precursor on Au(111) and Ag(111) and found that the activation energy is lower on inert Au(111) than on Ag(111). Combining scanning tunneling microscopy observations, synchrotron radiation photoemission spectroscopy measurements, and density functional theory calculations, we elucidate that the phenomenon arises from different molecule-substrate interactions. The molecular precursors anchor on Au(111) via Au-S interactions, which lead to weakening of the phenyl-S bonds. On the other hand, the molecular precursors anchor on Ag(111) via Ag-O interactions, resulting in the lifting of the S atoms. As a consequence, the activation barrier of the desulfonylation reactions is higher on Ag(111), although silver is generally more chemically active than gold. Our study not only reports a new type of on-surface chemical reaction but also clarifies the influence of detailed adsorption configurations on specific on-surface chemical reactions.


Subject(s)
Gold , Silver , Gold/chemistry , Silver/chemistry , Molecular Conformation , Adsorption
9.
Surg Endosc ; 36(6): 3732-3749, 2022 06.
Article in English | MEDLINE | ID: mdl-34406470

ABSTRACT

BACKGROUND: Several difficulty scoring systems (DSSs) have been proposed for evaluating difficulty of laparoscopic liver resection (LLR) and no study has validated their performance in a hepatocellular carcinoma (HCC)-only cohort at the same time. METHODS: All cases with HCC that underwent LLR from January 2015 to December 2020 in our center were retrospectively collected. Performance of the IWATE-DSS, Halls-DSS, Hasegawa-DSS, and Kawaguchi-DSS in predicting perioperative outcomes was evaluated. Subgroup analyses were conducted to compare perioperative outcomes between surgeons on the learning curve and surgeons that have gone through the learning curve. RESULTS: For all four DSSs, there were significant distributions of applying bleeding control, surgical time, estimated blood loss, postoperative major complications, and postoperative hospital stay among different groups of each DSS (P all < 0.05). Conversion to laparotomy or not was significantly distributed in different groups of the IWATE-DSS (P = 0.006) and Halls-DSS (P = 0.022), while it was not in the Hasegawa-DSS (P = 0.056) and Kawaguchi-DSS (P = 0.183). Trend tests showed that the conversion rates increased with higher DSS points in the IWATE-DSS (P < 0.001) and the Kawaguchi-DSS (P = 0.021), while not in the Halls-DSS (P = 0.064) and the Hasegawa-DSS (P = 0.068). In the medium and advanced/expert difficulty-level subgroups defined by the IWATE-DSS, there were larger estimated blood loss (P in medium-difficulty group = 0.009; P in the advanced/expert difficulty group = 0.004) and longer postoperative hospital stay (P in the medium-difficulty group = 0.012; P in the advanced/expert group = 0.035) in the learner-performed cases. CONCLUSIONS: All DSSs performed well in predicting applying bleeding control, surgical time, estimated blood loss, postoperative major complications, and postoperative hospital stay, while only the IWATE-DSS was able to predict whether conversion to laparotomy or not for HCC patients underwent LLR. The IWATE-DSS was also able to help surgeons on the LLR learning curve choose cases and guide clinical practices.


Subject(s)
Carcinoma, Hepatocellular , Laparoscopy , Liver Neoplasms , Carcinoma, Hepatocellular/complications , Carcinoma, Hepatocellular/surgery , Hepatectomy/adverse effects , Humans , Laparoscopy/adverse effects , Length of Stay , Liver Neoplasms/complications , Liver Neoplasms/surgery , Operative Time , Postoperative Complications/epidemiology , Postoperative Complications/etiology , Postoperative Complications/surgery , Postoperative Hemorrhage/surgery , Retrospective Studies
10.
Int J Clin Oncol ; 27(7): 1145-1153, 2022 Jul.
Article in English | MEDLINE | ID: mdl-35397755

ABSTRACT

BACKGROUND: The single progesterone receptor (PR)-positive phenotype (estrogen receptor (ER)-/PR + , sPR positive) is an infrequent and independent biological entity. However, the prognosis of patients with sPR-positive and her-2-negative phenotype is still controversial, and it is not always easy to decide treatment strategies for them. METHODS: Patients during 2010-2014 were identified from Surveillance, Epidemiology, and End Results (SEER) database. The Kaplan-Meier method was used to evaluate cancer-specific survival (CSS). The propensity score matching (PSM) method was used to balance differences of characteristics in groups. The Life-Table method was used to calculate 5-year CSS rates and the annual hazard rate of death (HRD). RESULTS: A total of 97,527 patients were included, and only 745 (0.76%) patients were sPR-positive phenotype. The majority of sPR-positive breast cancer were basal-like subtype. Survival analysis showed that the sPR-positive breast cancer had similar prognosis comparing to double hormonal receptor-negative (ER-/PR-, dHoR-negative) breast cancer, and had the highest HRD during the initial 1-2 years of follow-up, then maintained the HRD of almost zero during the late years of follow-up. CONCLUSIONS: The patients with sPR-positive and her-2-negative breast cancer, similar to dHoR-negative breast cancer, had a worse survival, and could benefit from chemotherapy significantly. However, the escalating endocrine therapy was not recommended for sPR-positive patients. The patients with sPR positive should be excluded from future clinical trials concerning endocrine therapy.


Subject(s)
Breast Neoplasms , Triple Negative Breast Neoplasms , Breast Neoplasms/drug therapy , Breast Neoplasms/genetics , Female , Humans , Prognosis , Receptor, ErbB-2/genetics , Receptors, Estrogen , Receptors, Progesterone , Survival Analysis
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