Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 65
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
J Am Chem Soc ; 146(2): 1423-1434, 2024 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-38171910

RESUMO

Cu-based catalysts hold promise for electrifying CO2 to produce methane, an extensively used fuel. However, the activity and selectivity remain insufficient due to the lack of catalyst design principles to steer complex CO2 reduction pathways. Herein, we develop a concept to design carbon-supported Cu catalysts by regulating Cu active sites' atomic-scale structures and engineering the carbon support's mesoscale architecture. This aims to provide a favorable local reaction microenvironment for a selective CO2 reduction pathway to methane. In situ X-ray absorption and Raman spectroscopy analyses reveal the dynamic reconstruction of nitrogen and hydroxyl-immobilized Cu3 (N,OH-Cu3) clusters derived from atomically dispersed Cu-N3 sites under realistic CO2 reduction conditions. The N,OH-Cu3 sites possess moderate *CO adsorption affinity and a low barrier for *CO hydrogenation, enabling intrinsically selective CO2-to-CH4 reduction compared to the C-C coupling with a high energy barrier. Importantly, a block copolymer-derived carbon fiber support with interconnected mesopores is constructed. The unique long-range mesochannels offer an H2O-deficient microenvironment and prolong the transport path for the CO intermediate, which could suppress the hydrogen evolution reaction and favor deep CO2 reduction toward methane formation. Thus, the newly developed catalyst consisting of in situ constructed N,OH-Cu3 active sites embedded into bicontinuous carbon mesochannels achieved an unprecedented Faradaic efficiency of 74.2% for the CO2 reduction to methane at an industry-level current density of 300 mA cm-2. This work explores effective concepts for steering desirable reaction pathways in complex interfacial catalytic systems via modulating active site structures at the atomic level and engineering pore architectures of supports on the mesoscale to create favorable microenvironments.

2.
Am J Hum Genet ; 108(8): 1466-1477, 2021 08 05.
Artigo em Inglês | MEDLINE | ID: mdl-34237282

RESUMO

Multiple morphological abnormalities of the sperm flagella (MMAF)-induced asthenoteratozoospermia is a common cause of male infertility. Previous studies have identified several MMAF-associated genes, highlighting the condition's genetic heterogeneity. To further define the genetic causes underlying MMAF, we performed whole-exome sequencing in a cohort of 643 Chinese MMAF-affected men. Bi-allelic DNAH10 variants were identified in five individuals with MMAF from four unrelated families. These variants were either rare or absent in public population genome databases and were predicted to be deleterious by multiple bioinformatics tools. Morphological and ultrastructural analyses of the spermatozoa obtained from men harboring bi-allelic DNAH10 variants revealed striking flagellar defects with the absence of inner dynein arms (IDAs). DNAH10 encodes an axonemal IDA heavy chain component that is predominantly expressed in the testes. Immunostaining analysis indicated that DNAH10 localized to the entire sperm flagellum of control spermatozoa. In contrast, spermatozoa from the men harboring bi-allelic DNAH10 variants exhibited an absence or markedly reduced staining intensity of DNAH10 and other IDA components, including DNAH2 and DNAH6. Furthermore, the phenotypes were recapitulated in mouse models lacking Dnah10 or expressing a disease-associated variant, confirming the involvement of DNAH10 in human MMAF. Altogether, our findings in humans and mice demonstrate that DNAH10 is essential for sperm flagellar assembly and that deleterious bi-allelic DNAH10 variants can cause male infertility with MMAF. These findings will provide guidance for genetic counseling and insights into the diagnosis of MMAF-associated asthenoteratozoospermia.


Assuntos
Astenozoospermia/complicações , Modelos Animais de Doenças , Dineínas/genética , Infertilidade Masculina/patologia , Mutação , Fenótipo , Espermatozoides/patologia , Alelos , Animais , Homozigoto , Humanos , Infertilidade Masculina/etiologia , Infertilidade Masculina/metabolismo , Masculino , Camundongos , Camundongos Knockout , Espermatozoides/metabolismo , Sequenciamento do Exoma
3.
Small ; : e2400221, 2024 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-38586921

RESUMO

Aqueous zinc-ion batteries (ZIBs) stand out as a promising next-generation electrochemical energy storage technology, offering notable advantages such as high specific capacity, enhanced safety, and cost-effectiveness. However, the application of aqueous electrolytes introduces challenges: Zn dendrite formation and parasitic reactions at the anode, as well as dissolution, electrostatic interaction, and by-product formation at the cathode. In addressing these electrode-centric problems, additive engineering has emerged as an effective strategy. This review delves into the latest advancements in electrolyte additives for ZIBs, emphasizing their role in resolving the existing issues. Key focus areas include improving morphology and reducing side reactions during battery cycling using synergistic effects of modulating anode interface regulation, zinc facet control, and restructuring of hydrogen bonds and solvation sheaths. Special attention is given to the efficacy of amino acids and zwitterions due to their multifunction to improve the cycling performance of batteries concerning cycle stability and lifespan. Additionally, the recent additive advancements are studied for low-temperature and extreme weather applications meticulously. This review concludes with a holistic look at the future of additive engineering, underscoring its critical role in advancing ZIB performance amidst the complexities and challenges of electrolyte additives.

4.
Small ; : e2311477, 2024 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-38554022

RESUMO

Seawater electrolysis is a promising but challenging strategy to generate carbon-neutral hydrogen. A grand challenge for hydrogen evolution reaction (HER) from alkaline seawater electrolysis is the development of efficient and stable electrocatalysts to overcome the limitation of sluggish kinetics. Here, a 3D nanorod hybrid catalyst is reported, which comprises heterostructure MoO2@NiMoO4 supported Ru nanoparticles (Ru/ MoO2@NiMoO4) with a size of ≈5 nm. Benefitting from the effect of strongly coupled interaction, Ru/MoO2@NiMoO4 catalyst exhibits a remarkable alkaline seawater hydrogen evolution performance, featured by a low overpotential of 184 mV at a current density of 1.0 A cm-2, superior to commercial Pt/C (338 mV). Experimental observations demonstrate that the heterostructure MoO2@NiMoO4 as an electron-accepting support makes the electron transfer from the Ru nanoparticles to MoO2, and thereby implements the electron redistribution of Ru site. Mechanistic analysis elucidates that the electron redistribution of active Ru site enhances the ability of hydrogen desorption, thereby promoting alkaline seawater HER kinetics and finally leading to a satisfactory catalysis performance at ampere-level current density of alkaline seawater electrolysis.

5.
J Environ Manage ; 355: 120547, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38452621

RESUMO

The synergistic partial-denitrification, anammox, and fermentation (SPDAF) process presents a promising solution to treat domestic and nitrate wastewaters. However, its capability to handle fluctuating C/N ratios (the ratios of COD to total inorganic nitrogen) in practical applications remains uncertain. In this study, the SPDAF process was operated for 236 days with C/N ratios of 0.7-3.5, and a high and stable efficiency of nitrogen removal (84.9 ± 7.8%) was achieved. The denitrification and anammox contributions were 6.1 ± 7.1% and 93.9 ± 7.1%, respectively. Batch tests highlighted the pivotal role of in situ fermentation at low biodegradable chemical oxygen demand (BCOD)/NO3- ratios. As the BCOD/NO3- ratios increased from 0 to 6, the NH4+ and NO3- removal rates increased, while the anammox contribution decreased from 100% to 80.1% but remained the primary pathway of nitrogen removal. The cooperation and balanced growth of denitrifying bacteria, anammox bacteria, and fermentation bacteria contributed to the system's robustness under fluctuating C/N ratios.


Assuntos
Nitratos , Águas Residuárias , Fermentação , Desnitrificação , Esgotos , Oxidação Anaeróbia da Amônia , Reatores Biológicos/microbiologia , Oxirredução , Nitrogênio/análise
6.
Angew Chem Int Ed Engl ; 63(12): e202317884, 2024 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-38150410

RESUMO

The electrochemical CO2 reduction reaction (CO2 RR) is a promising approach to achieving sustainable electrical-to-chemical energy conversion and storage while decarbonizing the emission-heavy industry. The carbon-supported, nitrogen-coordinated, and atomically dispersed metal sites are effective catalysts for CO generation due to their high activity, selectivity, and earth abundance. Here, we discuss progress, challenges, and opportunities for designing and engineering atomic metal catalysts from single to dual metal sites. Engineering single metal sites using a nitrogen-doped carbon model was highlighted to exclusively study the effect of carbon particle sizes, metal contents, and M-N bond structures in the form of MN4 moieties on catalytic activity and selectivity. The structure-property correlation was analyzed by combining experimental results with theoretical calculations to uncover the CO2 to CO conversion mechanisms. Furthermore, dual-metal site catalysts, inheriting the merits of single-metal sites, have emerged as a new frontier due to their potentially enhanced catalytic properties. Designing optimal dual metal site catalysts could offer additional sites to alter the surface adsorption to CO2 and various intermediates, thus breaking the scaling relationship limitation and activity-stability trade-off. The CO2 RR electrolysis in flow reactors was discussed to provide insights into the electrolyzer design with improved CO2 utilization, reaction kinetics, and mass transport.

7.
Angew Chem Int Ed Engl ; : e202405641, 2024 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-38818616

RESUMO

Compared to Ir, Ru-based catalysts often exhibited higher activity but suffered significant and rapid activity loss during the challenging oxygen evolution reaction (OER) in a corrosive acidic environment. Herein, we developed a hybrid MnRuOx catalyst in which the RuO2 microcrystalline regions serve as a supporting framework, and the amorphous MnRuOx phase fills the microcrystalline interstices. In particular, the MnRuOx-300 catalyst from an annealing temperature of 300 °C contains an optimal amorphous/crystalline heterostructure, providing substantial defects and active sites, facilitating efficient adsorption and conversion of OH-. In addition, the heterostructure leads to a relative increase of the d-band center close to the Fermin level, thus accelerating electron transfer with reduced charge transfer resistance at the active interface between crystalline and amorphous phases during the OER. The catalyst was further thoroughly evaluated under various operating conditions and demonstrated exceptional activity and stability for the OER, representing a promising solution to replace Ir in water electrolyzers.

8.
Hum Mol Genet ; 30(23): 2240-2254, 2021 11 16.
Artigo em Inglês | MEDLINE | ID: mdl-34231842

RESUMO

Asthenoteratospermia is a common cause of male infertility. Recent studies have revealed that CFAP65 mutations lead to severe asthenoteratospermia due to acrosome hypoplasia and flagellum malformations. However, the molecular mechanism underlying CFAP65-associated sperm malformation is largely unclear. Here, we initially examined the role of CFAP65 during spermiogenesis using Cfap65 knockout (Cfap65-/-) mice. The results showed that Cfap65-/- male mice exhibited severe asthenoteratospermia characterized by morphologically defective sperm heads and flagella. In Cfap65-/- mouse testes, hyper-constricted sperm heads were apparent in step 9 spermatids accompanied by abnormal manchette development, and acrosome biogenesis was abnormal in the maturation phase. Moreover, subsequent flagellar elongation was also severely affected and characterized by disrupted assembly of the mitochondrial sheath (MS) in Cfap65-/- male mice. Furthermore, the proteomic analysis revealed that the proteostatic system during acrosome formation, manchette organization and MS assembly was disrupted when CFAP65 was lost. Importantly, endogenous immunoprecipitation and immunostaining experiments revealed that CFAP65 may form a cytoplasmic protein network comprising MNS1, RSPH1, TPPP2, ZPBP1 and SPACA1. Overall, these findings provide insights into the complex molecular mechanisms of spermiogenesis by uncovering the essential roles of CFAP65 during sperm head shaping, acrosome biogenesis and MS assembly.


Assuntos
Acrossomo/metabolismo , Proteínas de Membrana/genética , Mitocôndrias/genética , Mitocôndrias/metabolismo , Espermatogênese , Animais , Flagelos/genética , Flagelos/metabolismo , Flagelos/patologia , Imuno-Histoquímica , Infertilidade Masculina/genética , Masculino , Proteínas de Membrana/metabolismo , Camundongos , Camundongos Knockout , Mitocôndrias/ultraestrutura , Mapeamento de Interação de Proteínas , Mapas de Interação de Proteínas , Cabeça do Espermatozoide/metabolismo , Cabeça do Espermatozoide/patologia , Cauda do Espermatozoide/metabolismo , Cauda do Espermatozoide/patologia , Cauda do Espermatozoide/ultraestrutura , Espermatogênese/genética , Testículo/metabolismo , Testículo/patologia
9.
Ther Drug Monit ; 45(6): 786-791, 2023 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-37296502

RESUMO

BACKGROUND: This study aimed to investigate the pharmacokinetic/pharmacodynamic (PK/PD) target attainment of various tigecycline dosing regimens in real-world patients with impaired liver function. METHODS: The clinical data and serum concentrations of tigecycline were extracted from the patients' electronic medical records. Patients were classified into Child-Pugh A, Child-Pugh B, and Child-Pugh C groups, according to the severity of liver impairment. Furthermore, the minimum inhibition concentration (MIC) distribution and PK/PD targets of tigecycline from the literature were used to obtain a proportion of PK/PD targets attainment of various tigecycline dosing regimens at different infected sites. RESULTS: The pharmacokinetic parameters revealed significantly higher values in moderate and severe liver failure (groups Child-Pugh B and Child-Pugh C) than those in mild impairment (Child-Pugh A). Considering the target area under the time-concentration curve (AUC 0-24 )/MIC ≥4.5 for patients with pulmonary infection, most patients with high-dose (100 mg, every 12 hours) or standard-dose (50 mg, every 12 hours) for tigecycline achieved the target in groups Child-Pugh A, B, and C. Considering the target AUC 0-24 /MIC ≥6.96 for patients with intra-abdominal infection, when MIC ≤1 mg/L, more than 80% of the patients achieved the target. For an MIC of 2-4 mg/L, only patients with high-dose tigecycline in groups Child-Pugh B and C attained the treatment target. Patients experienced a reduction in fibrinogen values after treatment with tigecycline. In group Child-Pugh C, all 6 patients developed hypofibrinogenemia. CONCLUSIONS: Severe hepatic impairment may attain higher PK/PD targets, but carries a high risk of adverse reactions.


Assuntos
Falência Hepática , Humanos , Tigeciclina , Área Sob a Curva , Antibacterianos/farmacocinética , Testes de Sensibilidade Microbiana
10.
Angew Chem Int Ed Engl ; 62(8): e202216490, 2023 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-36478521

RESUMO

Qiao and co-workers recently designed and interpreted the construction of high-density Pt single atoms in the Co3 O4 host with inter-site interactions via the Hard-Soft Acid-Base principle and further revealed the dynamic structure evolution process of the single atom sites by a series of in situ/ex situ spectroscopic techniques and theoretical computation.

11.
Angew Chem Int Ed Engl ; 62(10): e202215938, 2023 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-36507657

RESUMO

Unrestrained anthropogenic activities have severely disrupted the global natural nitrogen cycle, causing numerous energy and environmental issues. Electrocatalytic nitrogen transformation is a feasible and promising strategy for achieving a sustainable nitrogen economy. Synergistically combining multiple nitrogen reactions can realize efficient renewable energy storage and conversion, restore the global nitrogen balance, and remediate environmental crises. Here, we provide a unique aspect to discuss the intriguing nitrogen electrochemistry by linking three essential nitrogen-containing compounds (i.e., N2 , NH3 , and NO3 - ) and integrating four essential electrochemical reactions, i.e., the nitrogen reduction reaction (N2 RR), nitrogen oxidation reaction (N2 OR), nitrate reduction reaction (NO3 RR), and ammonia oxidation reaction (NH3 OR). This minireview also summarizes the acquired knowledge of rational catalyst design and underlying reaction mechanisms for these interlinked nitrogen reactions. We further underscore the associated clean energy technologies and a sustainable nitrogen-based economy.

12.
Angew Chem Int Ed Engl ; 62(43): e202307283, 2023 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-37338736

RESUMO

Upgrading CO2 into multi-carbon (C2+) compounds through the CO2 reduction reaction (CO2 RR) offers a practical approach to mitigate atmospheric CO2 while simultaneously producing high value chemicals. The reaction pathways for C2+ production involve multi-step proton-coupled electron transfer (PCET) and C-C coupling processes. By increasing the surface coverage of adsorbed protons (*Had ) and *CO intermediates, the reaction kinetics of PCET and C-C coupling can be accelerated, thereby promoting C2+ production. However, *Had and *CO are competitively adsorbed intermediates on monocomponent catalysts, making it difficult to break the linear scaling relationship between the adsorption energies of the *Had /*CO intermediate. Recently, tandem catalysts consisting of multicomponents have been developed to improve the surface coverage of *Had or *CO by enhancing water dissociation or CO2 -to-CO production on auxiliary sites. In this context, we provide a comprehensive overview of the design principles of tandem catalysts based on reaction pathways for C2+ products. Moreover, the development of cascade CO2 RR catalytic systems that integrate CO2 RR with downstream catalysis has expanded the range of potential CO2 upgrading products. Therefore, we also discuss recent advancements in cascade CO2 RR catalytic systems, highlighting the challenges and perspectives in these systems.

13.
Angew Chem Int Ed Engl ; 62(34): e202304797, 2023 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-37376764

RESUMO

Electrocatalytic nitrogen reduction reaction (NRR) under ambient conditions provides an intriguing pathway to convert N2 into NH3 . However, significant kinetic barriers of the NRR at low temperatures in desirable aqueous electrolytes remain a grand challenge due to the inert N≡N bond of the N2 molecule. Herein, we propose a unique strategy for in situ oxygen vacancy construction to address the significant trade-off between N2 adsorption and NH3 desorption by building a hollow shell structured Fe3 C/Fe3 O4 heterojunction coated with carbon frameworks (Fe3 C/Fe3 O4 @C). In the heterostructure, the Fe3 C triggers the oxygen vacancies of the Fe3 O4 component, which are likely active sites for the NRR. The design could optimize the adsorption strength of the N2 and Nx Hy intermediates, thus boosting the catalytic activity for the NRR. This work highlights the significance of the interaction between defect and interface engineering for regulating electrocatalytic properties of heterostructured catalysts for the challenging NRR. It could motivate an in-depth exploration to advance N2 reduction to ammonia.

14.
Angew Chem Int Ed Engl ; 62(10): e202215406, 2023 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-36593654

RESUMO

Cu-based catalysts have been widely applied in electroreduction of carbon dioxide (CO2 ER) to produce multicarbon (C2+ ) feedstocks (e.g., C2 H4 ). However, the high energy barriers for CO2 activation on the Cu surface is a challenge for a high catalytic efficiency and product selectivity. Herein, we developed an in situ *CO generation and spillover strategy by engineering single Ni atoms on a pyridinic N-enriched carbon support with a sodalite (SOD) topology (Ni-SOD/NC) that acted as a donor to feed adjacent Cu nanoparticles (NPs) with *CO intermediate. As a result, a high C2 H4 selectivity of 62.5 % and an industrial-level current density of 160 mA cm-2 at a low potential of -0.72 V were achieved. Our studies revealed that the isolated NiN3 active sites with adjacent pyridinic N species facilitated the *CO desorption and the massive *CO intermediate released from Ni-SOD/NC then overflowed to Cu NPs surface to enrich the *CO coverage for improving the selectivity of CO2 ER to C2 H4 .

15.
Anesthesiology ; 137(5): 568-585, 2022 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-36018576

RESUMO

BACKGROUND: Etomidate, barbiturates, alfaxalone, and propofol are anesthetics that allosterically modulate γ-aminobutyric acid type A (GABAA) receptors via distinct sets of molecular binding sites. Two-state concerted coagonist models account for anesthetic effects and predict supra-additive interactions between drug pairs acting at distinct sites. Some behavioral and molecular studies support these predictions, while other findings suggest potentially complex anesthetic interactions. We therefore evaluated interactions among four anesthetics in both animals and GABAA receptors. METHODS: The authors used video assessment of photomotor responses in zebrafish larvae and isobolography to evaluate hypnotic drug pair interactions. Voltage clamp electrophysiology and allosteric shift analysis evaluated coagonist interactions in α1ß3γ2L receptors activated by γ-aminobutyric acid (GABA) versus anesthetics [log(d, AN):log(d, GABA) ratio]. Anesthetic interactions at concentrations relevant to zebrafish were assessed in receptors activated with low GABA. RESULTS: In zebrafish larvae, etomidate interacted additively with both propofol and the barbiturate R-5-allyl-1-methyl m-trifluoromethyl mephobarbital (R-mTFD-MPAB; mean ± SD α = 1.0 ± 0.07 and 0.96 ± 0.11 respectively, where 1.0 indicates additivity), while the four other drug pairs displayed synergy (mean α range 0.76 to 0.89). Electrophysiologic allosteric shifts revealed that both propofol and R-mTFD-MPAB modulated etomidate-activated receptors much less than GABA-activated receptors [log(d, AN):log(d, GABA) ratios = 0.09 ± 0.021 and 0.38 ± 0.024, respectively], while alfaxalone comparably modulated receptors activated by GABA or etomidate [log(d) ratio = 0.87 ± 0.056]. With low GABA activation, etomidate combined with alfaxalone was supra-additive (n = 6; P = 0.023 by paired t test), but etomidate plus R-mTFD-MPAB or propofol was not. CONCLUSIONS: In both zebrafish and GABAA receptors, anesthetic drug pairs interacted variably, ranging from additivity to synergy. Pairs including etomidate displayed corresponding interactions in animals and receptors. Some of these results challenge simple two-state coagonist models and support alternatives where different anesthetics may stabilize distinct receptor conformations, altering the effects of other drugs.


Assuntos
Anestésicos , Etomidato , Propofol , Animais , Etomidato/farmacologia , Etomidato/metabolismo , Peixe-Zebra/metabolismo , Receptores de GABA/metabolismo , Mefobarbital , Receptores de GABA-A , Anestésicos/farmacologia , Propofol/farmacologia , Barbitúricos/farmacologia , Sítios de Ligação , Hipnóticos e Sedativos/farmacologia , Ácido gama-Aminobutírico , Eletrofisiologia
16.
Angew Chem Int Ed Engl ; 61(45): e202210753, 2022 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-35997542

RESUMO

Directly splitting seawater to produce hydrogen provides a promising pathway for energy and environmental sustainability. However, current seawater splitting faces many challenges because of the sluggish kinetics, the presence of impurities, membrane contamination, and the competitive chloride oxidation reaction at the anode, which makes it more difficult than freshwater splitting. This Review firstly introduces the basic mechanisms of the anode and cathode reactions during seawater splitting. We critically analyze the primary principles for designing catalysts for seawater splitting in terms of both the hydrogen and oxygen evolution reactions, including with noble metal, noble metal free, and metal-free catalysts. Strategies to design effective catalysts, such as active site population, synergistic effect regulation, and surface engineering, are discussed. Furthermore, promises, perspectives, and challenges in developing seawater splitting technologies for clean hydrogen generation are summarized.

17.
Angew Chem Int Ed Engl ; 61(28): e202205632, 2022 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-35470950

RESUMO

Carbon-supported nitrogen-coordinated single-metal site catalysts (i.e., M-N-C, M: Fe, Co, or Ni) are active for the electrochemical CO2 reduction reaction (CO2 RR) to CO. Further improving their intrinsic activity and selectivity by tuning their N-M bond structures and coordination is limited. Herein, we expand the coordination environments of M-N-C catalysts by designing dual-metal active sites. The Ni-Fe catalyst exhibited the most efficient CO2RR activity and promising stability compared to other combinations. Advanced structural characterization and theoretical prediction suggest that the most active N-coordinated dual-metal site configurations are 2N-bridged (Fe-Ni)N6 , in which FeN4 and NiN4 moieties are shared with two N atoms. Two metals (i.e., Fe and Ni) in the dual-metal site likely generate a synergy to enable more optimal *COOH adsorption and *CO desorption than single-metal sites (FeN4 or NiN4 ) with improved intrinsic catalytic activity and selectivity.

18.
Small ; 17(16): e2005148, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33448131

RESUMO

The electrochemical CO2 reduction reaction (CO2 RR) is a promising strategy to achieve electrical-to-chemical energy storage while closing the global carbon cycle. The carbon-supported single-atom catalysts (SACs) have great potential for electrochemical CO2 RR due to their high efficiency and low cost. The metal centers' performance is related to the local coordination environment and the long-range electronic intercalation from the carbon substrates. This review summarizes the recent progress on the synthesis of carbon-supported SACs and their application toward electrocatalytic CO2 reduction to CO and other C1 and C2 products. Several SACs are involved, including MNx catalysts, heterogeneous molecular catalysts, and the covalent organic framework (COF) based SACs. The controllable synthesis methods for anchoring single-atom sites on different carbon supports are introduced, focusing on the influence that precursors and synthetic conditions have on the final structure of SACs. For the CO2 RR performance, the intrinsic activity difference of various metal centers and the corresponding activity enhancement strategies via the modulation of the metal centers' electronic structure are systematically summarized, which may help promote the rational design of active and selective SACs for CO2 reduction to CO and beyond.

19.
J Craniofac Surg ; 32(7): 2479-2483, 2021 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-34074929

RESUMO

BACKGROUND: To assess surgeries with the endoscope-navigation system (ENS) in patients who underwent traumatic optic neuropathy (TON) and find predictors for best corrected visual acuity (BCVA) outcomes. METHODS: The clinical data of 96 consecutive TON patients (96 eyes) who underwent decompression surgery with ENS in the Department of Ophthalmology, Shanghai Ninth People's Hospital, from January 2013 to December 2019 were retrospectively reviewed and analyzed. A binary logistic regression was performed to establish a predictive model for BCVA after treatment as TON outcome. RESULTS: By practicing ENS, 49/96 (51.0%) TON patients got improvement in BCVA, whereas the improvement rate of patients with BCVA of light perception or better was 72.5% (29/40). Hemorrhage within the postethmoid and/or sphenoid sinus, orbital fracture, time interval between trauma and treatment, and BCVA before treatment were predictors for BCVA improvement in TON patients by practicing ENS surgery. The area under raw current curves of the predictive model was 0.826. CONCLUSIONS: Surgeries with the ENS showed positive outcomes for TON patients, especially for those with better BCVA before treatment, shorter time interval between trauma and treatment, without orbital fracture or hemorrhage within the postethmoid and/or sphenoid sinus.


Assuntos
Traumatismos do Nervo Óptico , China , Descompressão Cirúrgica , Endoscópios , Humanos , Traumatismos do Nervo Óptico/cirurgia , Estudos Retrospectivos , Acuidade Visual
20.
J Integr Plant Biol ; 62(4): 398-402, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31702097

RESUMO

The widely used Streptococcus pyogenes Cas9 (SpCas9) requires NGG as a protospacer adjacent motif (PAM) for genome editing. Although SpCas9 is a powerful genome-editing tool, its use has been limited on the targetable genomic locus lacking NGG PAM. The SpCas9 variants xCas9 and Cas9-NG have been developed to recognize NG, GAA, and GAT PAMs in human cells. Here, we show that xCas9 cannot recognize NG PAMs in tomato, and Cas9-NG can recognize some of our tested NG PAMs in the tomato and Arabidopsis genomes. In addition, we engineered SpCas9 (XNG-Cas9) based on mutations from both xCas9 and Cas9-NG, and found that XNG-Cas9 can efficiently mutagenize endogenous target sites with NG, GAG, GAA, and GAT PAMs in the tomato or Arabidopsis genomes. The PAM compatibility of XNG-Cas9 is the broadest reported to date among Cas9s (SpCas9 and Cas9-NG) active in plant.


Assuntos
Arabidopsis/genética , Proteína 9 Associada à CRISPR/metabolismo , Sistemas CRISPR-Cas/genética , Edição de Genes , Genoma de Planta , Solanum lycopersicum/genética , Protoplastos/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA