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1.
Proc Natl Acad Sci U S A ; 121(11): e2317702121, 2024 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-38446850

RESUMO

The electro-Fenton process is a state-of-the-art water treatment technology used to remove organic contaminants. However, the low O2 utilization efficiency (OUE, <1%) and high energy consumption remain the biggest obstacles to practical application. Here, we propose a local O2 concentrating (LOC) approach to increase the OUE by over 11-fold compared to the conventional simple O2 diffusion route. Due to the well-designed molecular structure, the LOC approach enables direct extraction of O2 from the bulk solution to the reaction interface; this eliminates the need to pump O2/air to overcome the sluggish O2 mass transfer and results in high Faradaic efficiencies (~50%) even under natural air diffusion conditions. Long-term operation of a flow-through pilot device indicated that the LOC approach saved more than 65% of the electric energy normally consumed in treating actual industrial wastewater, demonstrating the great potential of this system-level design to boost the electro-Fenton process for energy-efficient water remediation.

2.
Proc Natl Acad Sci U S A ; 120(3): e2209979120, 2023 01 17.
Artigo em Inglês | MEDLINE | ID: mdl-36626554

RESUMO

The electrolysis of nitrate reduction to ammonia (NRA) is promising for obtaining value-added chemicals and mitigating environmental concerns. Recently, catalysts with high-performance ammonia synthesis from nitrate has been achieved under alkaline or acidic conditions. However, NRA in neutral solution still suffers from the low yield rate and selectivity of ammonia due to the low binding affinity and nucleophilicity of NO3-. Here, we confirmed that the in-situ-generated Fe(II) ions existed as specifically adsorbed cations in the inner Helmholtz plane (IHP) with a low redox potential. Inspired by this, a strategy (Fe-IHP strategy) was proposed to enhance NRA activity by tuning the affinity of the electrode-electrolyte interface. The specifically adsorbed Fe(II) ions [SA-Fe(II)] greatly alleviated the electrostatic repulsion around the interfaceresulting in a 10-fold lower in the adsorption-free energy of NO3- when compared to the case without SA-Fe(II). Meanwhile, the modulated interface accelerated the kinetic mass transfer process by 25 folds compared to the control. Under neutral conditions, a Faraday efficiency of 99.6%, a selectivity of 99%, and an extremely high NH3 yield rate of 485.8 mmol h-1 g-1 FeOOH were achieved. Theoretical calculations and in-situ Raman spectroscopy confirmed the electron-rich state of the SA-Fe(II) donated to p orbitals of N atom and favored the hydrogenation of *NO to *NOH for promoting the formation of high-selectivity ammonia. In sum, these findings complement the textbook on the specific adsorption of cations and provide insights into the design of low-cost NRA catalysts with efficient ammonia synthesis.


Assuntos
Amônia , Nitratos , Eletrólitos , Adsorção , Ferro , Compostos Ferrosos
3.
Proc Natl Acad Sci U S A ; 120(34): e2305604120, 2023 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-37585465

RESUMO

Electrochemical conversion of N2 into ammonia presents a sustainable pathway to produce hydrogen storage carrier but yet requires further advancement in electrocatalyst design and electrolyzer integration. This technology suffers from low selectivity and yield owing to the extremely strong N≡N bond and the exceptionally low solubility of N2 in aqueous systems. A high NH3 synthesis performance is restricted by the high activation energy of N≡N bond and the supply insufficiency of N2 to active sites. This paper describes the introduction of electron-rich Bi0 sites into Ag catalysts with a high-pressure electrolyzer that enables a dramatically enhanced Faradaic efficiency of 44.0% and yield of 28.43 µg cm-2 h-1 at 4.0 MPa. Combined with density functional theory results, in situ attenuated total reflectance surface-enhanced infrared absorption spectroscopy demonstrates that N2 reduction reaction follows an associative mechanism, in which a high coverage of N-N bond and -NH2 intermediates suggest electron-rich Bi0 boosts sound activation of N2 molecules and low hydrogenation barrier. The proposed strategy of engineering electrochemical catalysts and devices provides powerful guidelines for achieving industrial-level green ammonia production.

4.
Nature ; 569(7757): 509-513, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-31068699

RESUMO

A universal gain-of-function approach for selective and temporal control of protein activity in living systems is crucial to understanding dynamic cellular processes. Here we report development of a computationally aided and genetically encoded proximal decaging (hereafter, CAGE-prox) strategy that enables time-resolved activation of a broad range of proteins in living cells and mice. Temporal blockage of protein activity was computationally designed and realized by genetic incorporation of a photo-caged amino acid in proximity to the functional site of the protein, which can be rapidly removed upon decaging, resulting in protein re-activation. We demonstrate the wide applicability of our method on diverse protein families, which enabled orthogonal tuning of cell signalling and immune responses, temporal profiling of proteolytic substrates upon caspase activation as well as the development of protein-based pro-drug therapy. We envision that CAGE-prox will open opportunities for the gain-of-function study of proteins and dynamic biological processes with high precision and temporal resolution.


Assuntos
Sobrevivência Celular , Proteínas/metabolismo , Animais , Caspase 3/genética , Caspase 3/metabolismo , Linhagem Celular , Ativação Enzimática , Mutação com Ganho de Função , Humanos , Masculino , Camundongos , Neoplasias/tratamento farmacológico , Fosfotransferases/metabolismo , Pró-Fármacos/metabolismo , Pró-Fármacos/uso terapêutico , Proteínas/genética , Proteínas/imunologia , Proteínas/uso terapêutico , Proteólise , Proteômica , Transdução de Sinais , Fatores de Tempo
5.
Nano Lett ; 24(26): 7919-7926, 2024 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-38836594

RESUMO

Schottky diode, capable of ultrahigh frequency operation, plays a critical role in modern communication systems. To develop cost-effective and widely applicable high-speed diodes, researchers have delved into thin-film semiconductors. However, a performance gap persists between thin-film diodes and conventional bulk semiconductor-based ones. Featuring high mobility and low permittivity, indium-tin-oxide has emerged to bridge this gap. Nevertheless, due to its high carrier concentration, indium-tin-oxide has predominantly been utilized as electrode rather than semiconductor. In this study, a remarkable quantum confinement induced dedoping phenomenon was discovered during the aggressive indium-tin-oxide thickness downscaling. By leveraging such a feature to change indium-tin-oxide from metal-like into semiconductor-like, in conjunction with a novel heterogeneous lateral design facilitated by an innovative digital etch, we demonstrated an indium-tin-oxide Schottky diode with a cutoff frequency reaching terahertz band. By pushing the boundaries of thin-film Schottky diodes, our research offers a potential enabler for future fifth-generation/sixth-generation networks, empowering diverse applications.

6.
J Proteome Res ; 23(5): 1593-1602, 2024 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-38626392

RESUMO

With the rapid expansion of sequencing of genomes, the functional annotation of proteins becomes a bottleneck in understanding proteomes. The Chromosome-centric Human Proteome Project (C-HPP) aims to identify all proteins encoded by the human genome and find functional annotations for them. However, until now there are still 1137 identified human proteins without functional annotation, called uPE1 proteins. Sequence alignment was insufficient to predict their functions, and the crystal structures of most proteins were unavailable. In this study, we demonstrated a new functional annotation strategy, AlphaFun, based on structural alignment using deep-learning-predicted protein structures. Using this strategy, we functionally annotated 99% of the human proteome, including the uPE1 proteins and missing proteins, which have not been identified yet. The accuracy of the functional annotations was validated using the known-function proteins. The uPE1 proteins shared similar functions to the known-function PE1 proteins and tend to express only in very limited tissues. They are evolutionally young genes and thus should conduct functions only in specific tissues and conditions, limiting their occurrence in commonly studied biological models. Such functional annotations provide hints for functional investigations on the uPE1 proteins. This proteome-wide-scale functional annotation strategy is also applicable to any other species.


Assuntos
Anotação de Sequência Molecular , Proteoma , Humanos , Proteoma/genética , Proteoma/metabolismo , Proteoma/análise , Proteoma/química , Aprendizado Profundo , Alinhamento de Sequência , Genoma Humano , Proteômica/métodos , Bases de Dados de Proteínas
7.
J Proteome Res ; 23(7): 2323-2331, 2024 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-38865581

RESUMO

The Chromosome-Centric Human Proteome Project (C-HPP) aims to identify all proteins encoded by the human genome. Currently, the human proteome still contains approximately 2000 PE2-PE5 proteins, referring to annotated coding genes that lack sufficient protein-level evidence. During the past 10 years, it has been increasingly difficult to identify PE2-PE5 proteins in C-HPP approaches due to the limited occurrence. Therefore, we proposed that reanalyzing massive MS data sets in repository with newly developed algorithms may increase the occurrence of the peptides of these proteins. In this study, we downloaded 1000 MS data sets via the ProteomeXchange database. Using pFind software, we identified peptides referring to 1788 PE2-PE5 proteins. Among them, 11 PE2 and 16 PE5 proteins were identified with at least 2 peptides, and 12 of them were identified using 2 peptides in a single data set, following the criteria of the HPP guidelines. We found translation evidence for 16 of the 11 PE2 and 16 PE5 proteins in our RNC-seq data, supporting their existence. The properties of the PE2 and PE5 proteins were similar to those of the PE1 proteins. Our approach demonstrated that mining PE2 and PE5 proteins in massive data repository is still worthy, and multidata set peptide identifications may support the presence of PE2 and PE5 proteins or at least prompt additional studies for validation. Extremely high throughput could be a solution to finding more PE2 and PE5 proteins.


Assuntos
Bases de Dados de Proteínas , Proteoma , Software , Humanos , Proteoma/análise , Proteoma/genética , Algoritmos , Espectrometria de Massas/métodos , Proteômica/métodos , Peptídeos/genética , Peptídeos/análise , Peptídeos/química , Genoma Humano
8.
J Am Chem Soc ; 146(3): 2122-2131, 2024 01 24.
Artigo em Inglês | MEDLINE | ID: mdl-38190443

RESUMO

Bioconjugation chemistry has emerged as a powerful tool for the modification of diverse biomolecules under mild conditions. Tetrazole, initially proposed as a bioorthogonal photoclick handle for 1,3-dipolar cyclization with alkenes, was later demonstrated to possess broader photoreactivity with carboxylic acids, serving as a versatile bioconjugation and photoaffinity labeling probe. In this study, we unexpectedly discovered and validated the photoreactivity between tetrazole and primary amine to afford a new 1,2,4-triazole cyclization product. Given the significance of functionalized N-heterocycles in medicinal chemistry, we successfully harnessed the serendipitously discovered reaction to synthesize both pharmacologically relevant DNA-encoded chemical libraries (DELs) and small molecule compounds bearing 1,2,4-triazole scaffolds. Furthermore, the mild reaction conditions and stable 1,2,4-triazole linkage found broad application in photoinduced bioconjugation scenarios, spanning from intramolecular peptide macrocyclization and templated DNA reaction cross-linking to intermolecular photoaffinity labeling of proteins. Triazole cross-linking products on lysine side chains were identified in tetrazole-labeled proteins, refining the comprehensive understanding of the photo-cross-linking profiles of tetrazole-based probes. Altogether, this tetrazole-amine bioconjugation expands the current bioconjugation toolbox and creates new possibilities at the interface of medicinal chemistry and chemical biology.


Assuntos
Aminas , Proteínas , Aminas/química , Ciclização , Proteínas/química , Tetrazóis/química , DNA , Química Click
9.
NMR Biomed ; 37(3): e5068, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37964107

RESUMO

Inductively coupled radiofrequency (RF) coils are an inexpensive and simple method to realize wireless RF coils in magnetic resonance imaging (MRI), which can significantly ease the MRI scan setup and improve patient comfort because they do not require bulky components such as cables, baluns, preamplifiers, and connectors. However, volume-type wireless coils are typically operated in transmit/receive mode because detuning such coils is much more challenging due to their complex structure and multiple resonant modes. Meanwhile, adding too many detuning circuits to a wireless coil would decrease the coil's quality factor, impair the signal-to-noise ratio, and increase the cost. In this work, we proposed, constructed, and tested a novel wireless volume coil based on the Litzcage design for 1.5-T head imaging. Being an inductively coupled coil, it has a much simpler structure, resulting in a lighter weight and less bulky design. Despite its simpler structure, it exhibits comparable imaging performance with a commercial receive array, providing an alternative to conventional wired coils with a high cost and complex structure. The unique figure-of-8 conductor pattern within the rungs ensures that the proposed wireless Litzcage can be efficiently detuned with minimal detuning circuits.


Assuntos
Imageamento por Ressonância Magnética , Ondas de Rádio , Humanos , Imageamento por Ressonância Magnética/métodos , Razão Sinal-Ruído , Desenho de Equipamento , Imagens de Fantasmas
10.
Environ Sci Technol ; 58(17): 7643-7652, 2024 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-38573006

RESUMO

Electrochemical-induced precipitation is a sustainable approach for tap-water softening, but the hardness removal performance and energy efficiency are vastly limited by the ultraslow ion transport and the superlow local HCO3-/Ca2+ ratio compared to the industrial scenarios. To tackle the challenges, we herein report an energy-efficient electrochemical tap-water softening strategy by utilizing an integrated cathode-anode-cathode (CAC) reactor in which the direction of the electric field is reversed to that of the flow field in the upstream cell, while the same in the downstream cell. As a result, the transport of ions, especially HCO3-, is significantly accelerated in the downstream cell under a flow field. The local HCO3-/Ca2+ ratio is increased by 1.5 times, as revealed by the finite element numerical simulation and in situ imaging. In addition, a continuous flow electrochemical system with an integrated CAC reactor is operated for 240 h to soften tap water. Experiments show that a much lower cell voltage (9.24 V decreased) and energy consumption (28% decreased) are obtained. The proposed ion-transport enhancement strategy by coupled electric and flow fields provides a new perspective on developing electrochemical technologies to meet the flexible and economic demand for tap-water softening.


Assuntos
Transporte de Íons , Eletricidade , Água Potável , Eletrodos , Purificação da Água/métodos , Técnicas Eletroquímicas/métodos
11.
Environ Sci Technol ; 58(25): 11185-11192, 2024 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-38869092

RESUMO

Electrocatalytic hydrogen atom-hydroxyl radical (H*-·OH) redox system is a promising approach for contaminant removal and mineralization. However, its working mechanism, especially the effect of H*, remains unclear, hindering its practical application. Herein, we constructed an electrochemical reactor equipped with our self-made Pd-loaded Ti/TiO2 nanotube cathode and a commercial boron-doped diamond anode. After fulfilling the electrode characterization and free radical detection, we employed coumarin and 7-azido-4-methylcoumarin as probes to confirm the participation of H* in the transformation of organic compounds. A comprehensive study on the degradation kinetics, reaction, and mineralization mechanisms using benzoic acid (BA) and 4-chlorophenol (4-CP) as model compounds was further conducted. The rate constants and total organic carbon removal of BA and 4-CP in the redox system increased compared with those of the individual oxidation and reduction processes. Theoretical calculations demonstrate that H* opens up alternative pathways for BA and 4-CP ring cleavage, forming quinones as reactive intermediates. Furthermore, H* facilitates the mineralization of the typical intermediates, maleic acid and fumaric acid, through C=C bond addition and H-abstraction from the 1,1-diol structure. The presence of H* provides alternative pathways for pollutant transformation, consequently reducing the treatment duration.


Assuntos
Hidrogênio , Oxirredução , Hidrogênio/química , Cinética
12.
Surg Endosc ; 2024 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-38977502

RESUMO

BACKGROUND: The safety and efficacy of robotic liver resection (RLR) for patients with hepatocellular carcinoma (HCC) have been reported worldwide. However, the exact role of RLR in HCC patients with liver cirrhosis is not sufficiently determined. METHODS: We conducted a retrospective study on consecutive patients with cirrhosis or non-cirrhosis who received RLR for HCC from 2018 to 2023. Data on patients' demographics and perioperative outcomes were collected and analyzed. Propensity score matching (PSM) analysis was performed. Multivariate logistic regression analysis was performed to determine the risk factors of prolonged postoperative length of stay (LOS) and morbidity. RESULTS: Of the 571 patients included, 364 (64%) had cirrhosis. Among the cirrhotic patients, 48 (13%) were classified as Child-Pugh B. After PSM, the cirrhosis and non-cirrhosis group (n = 183) had similar operative time, estimated blood loss, postoperative blood transfusion, LOS, overall morbidity (p > 0.05). In addition, the intraoperative and postoperative outcomes were similar between the two groups in the subgroup analyses of patients with tumor size ≥ 5 cm, major hepatectomy, and high/expert IWATE difficulty grade. However, patients with Child-Pugh B cirrhosis had longer LOS and more overall morbidity than that of Child-Pugh A. Child-Pugh B cirrhosis, ASA score > 2, longer operative time, and multiple tumors were risk factors of prolonged LOS or morbidity in patients with cirrhosis. CONCLUSION: The presence of Child-Pugh A cirrhosis didn't significantly influence the difficulty and perioperative outcomes of RLR for selected patients with HCC. However, even in high-volume center, Child-Pugh B cirrhosis was a risk factor for poor postoperative outcomes.

13.
BMC Anesthesiol ; 24(1): 176, 2024 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-38760677

RESUMO

BACKGROUND: The role of mechanical power on pulmonary outcomes after thoracic surgery with one-lung ventilation was unclear. We investigated the association between mechanical power and postoperative pulmonary complications in patients undergoing thoracoscopic lung resection surgery. METHODS: In this single-center, prospective observational study, 622 patients scheduled for thoracoscopic lung resection surgery were included. Volume control mode with lung protective ventilation strategies were implemented in all participants. The primary endpoint was a composite of postoperative pulmonary complications during hospital stay. Multivariable logistic regression models were used to evaluate the association between mechanical power and outcomes. RESULTS: The incidence of pulmonary complications after surgery during hospital stay was 24.6% (150 of 609 patients). The multivariable analysis showed that there was no link between mechanical power and postoperative pulmonary complications. CONCLUSIONS: In patients undergoing thoracoscopic lung resection with standardized lung-protective ventilation, no association was found between mechanical power and postoperative pulmonary complications. TRIAL REGISTRATION: Trial registration number: ChiCTR2200058528, date of registration: April 10, 2022.


Assuntos
Ventilação Monopulmonar , Complicações Pós-Operatórias , Humanos , Estudos Prospectivos , Masculino , Feminino , Ventilação Monopulmonar/métodos , Complicações Pós-Operatórias/epidemiologia , Complicações Pós-Operatórias/etiologia , Pessoa de Meia-Idade , Idoso , Pneumonectomia/efeitos adversos , Pneumonectomia/métodos , Toracoscopia/métodos , Pneumopatias/etiologia , Pneumopatias/epidemiologia , Cirurgia Torácica Vídeoassistida/métodos , Cirurgia Torácica Vídeoassistida/efeitos adversos
14.
Chem Soc Rev ; 52(5): 1549-1590, 2023 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-36602188

RESUMO

Biomimetic science has attracted great interest in the fields of chemistry, biology, materials science, and energy. Biomimetic mineralization is the process of synthesizing inorganic minerals under the control of organic molecules or biomolecules under mild conditions. Peptides are the motifs that constitute proteins, and can self-assemble into various hierarchical structures and show a high affinity for inorganic substances. Therefore, peptides can be used as building blocks for the synthesis of functional biomimetic materials. With the participation of peptides, the morphology, size, and composition of mineralized materials can be controlled precisely. Peptides not only provide well-defined templates for the nucleation and growth of inorganic nanomaterials but also have the potential to confer inorganic nanomaterials with high catalytic efficiency, selectivity, and biotherapeutic functions. In this review, we systematically summarize research progress in the formation mechanism, nanostructural manipulation, and applications of peptide-templated mineralized materials. These can further inspire researchers to design structurally complex and functionalized biomimetic materials with great promising applications.


Assuntos
Materiais Biomiméticos , Nanoestruturas , Biomimética , Peptídeos/química , Proteínas , Nanoestruturas/química , Materiais Biomiméticos/química
15.
Chem Soc Rev ; 52(14): 4644-4671, 2023 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-37325843

RESUMO

Hydrogen is an essential energy carrier which will address the challenges posed by the energy crisis and climate change. Photoelectrochemical water splitting (PEC) is an important method for producing solar-powered hydrogen. The PEC tandem configuration harnesses sunlight as the exclusive energy source to drive both the hydrogen (HER) and oxygen evolution reactions (OER), simultaneously. Therefore, PEC tandem cells have been developed and gained tremendous interest in recent decades. This review describes the current status of the development of tandem cells for unbiased photoelectrochemical water splitting. The basic principles and prerequisites for constructing PEC tandem cells are introduced first. We then review various single photoelectrodes for use in water reduction or oxidation, and highlight the current state-of-the-art discoveries. Second, a close look into recent developments of PEC tandem cells in water splitting is provided. Finally, a perspective on the key challenges and prospects for the development of tandem cells for unbiased PEC water splitting are given.

16.
Nano Lett ; 23(24): 11601-11607, 2023 Dec 27.
Artigo em Inglês | MEDLINE | ID: mdl-38063776

RESUMO

Two-dimensional (2D) semiconductors have attracted great attention as a novel class of gain materials for low-threshold, on-chip coherent light sources. Despite several experimental reports on lasing, the underlying gain mechanism of 2D materials remains elusive due to a lack of key information, including modal gain and the confinement factor. Here, we demonstrate a novel approach to directly determine the absorption coefficient of monolayer WS2 by characterizing the whispering gallery modes in a van der Waals microdisk cavity. By exploiting the cavity's high intrinsic quality factor of 2.5 × 104, the absorption coefficient spectrum and confinement factor are experimentally resolved with unprecedented accuracy. The excitonic gain reduces the WS2 absorption coefficient by 2 × 104 cm-1 at room temperature, and the experimental confinement factor is found to agree with the theoretical prediction. These results are essential for unveiling the gain mechanism in emergent, low-threshold 2D-semiconductor-based laser devices.

17.
J Environ Sci (China) ; 146: 118-126, 2024 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38969440

RESUMO

With the increasing demand of recycling disposal of industrial wastewater, oil-in-water (O/W) emulsion has been paid much attention in recent years owing to its high oil content. However, due to the presence of surfactant and salt, the emulsion was usually stable with complex physicochemical interfacial properties leading to increased processing difficulty. Herein, a novel flow-through electrode-based demulsification reactor (FEDR) was well designed for the treatment of saline O/W emulsion. In contrast to 53.7% for electrical demulsification only and 80.3% for filtration only, the COD removal efficiency increased to 92.8% under FEDR system. Moreover, the pore size of electrode and the applied voltage were two key factors that governed the FEDR demulsification performance. By observing the morphology of oil droplets deposited layer after different operation conditions and the behavior of oil droplets at the electrode surface under different voltage conditions, the mechanism was proposed that the oil droplets first accumulated on the surface of flow-through electrode by sieving effect, subsequently the gathered oil droplets could further coalesce with the promoting effect of the anode, leading to a high-performing demulsification. This study offers an attractive option of using flow-through electrode to accomplish the oil recovery with simultaneous water purification.


Assuntos
Eletrodos , Filtração , Eliminação de Resíduos Líquidos , Purificação da Água , Purificação da Água/métodos , Filtração/métodos , Eliminação de Resíduos Líquidos/métodos , Óleos/química , Águas Residuárias/química , Poluentes Químicos da Água/química , Emulsões/química , Técnicas Eletroquímicas/métodos , Técnicas Eletroquímicas/instrumentação
18.
Angew Chem Int Ed Engl ; 63(17): e202401077, 2024 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-38456382

RESUMO

Circularly polarized luminescence (CPL) plays a pivotal role in cutting-edge display and information technologies. Currently achieving precise color control and dynamic signal regulation in CPL still remains challenging due to the elusory relationship between fluorescence and chirality. Inspired by the natural mechanisms governing color formation and chiral interaction, we proposed an addition-subtraction principle theory to address this issue. Three fluorene-based polymers synthesized by Suzuki polycondensation with different electron-deficient monomers exhibit similar structures and UV/Vis absorption, but distinct fluorescence emissions due to intramolecular charge transfer. Based on this, precise-color CPL-active films are obtained through quantitative supramolecular co-assembly directed by addition principle. Particularly, an ideal white-emitting CPL film (CIE coordinates: (0.33, 0.33)) is facilely fabricated with a high quantum yield of 80.8 % and a dissymmetry factor (glum) of 1.4×10-2. Structural analysis reveals that the ordered stacking orientation favors higher glum. Furthermore, to address the dynamically regulated challenge, the comparable subtraction principle is proposed, involving a contactless chiral communication between excited and ground states. The representative system consisting of as-prepared fluorene-based polymers and chirality-selective absorption azobenzene (Azo)-containing polymers is constructed, achieving CPL weakening, reversal, and enhancement. Finally, a switchable quick response code is realized based on trans-cis isomerization of Azo moiety.

19.
Angew Chem Int Ed Engl ; 63(12): e202318924, 2024 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-38270897

RESUMO

Singlet oxygen (1 O2 ) plays a significant role in environmental and biomedical disinfection fields. Electrocatalytic processes hold great potential for 1 O2 generation, but remain challenging. Herein, a facile Ni doping converted spin-state transition approach is reported for boosting 1 O2 production. Magnetic analysis and theoretical calculations reveal that Ni occupied at the octahedral site of Co3 O4 can effectively induce a low-to-high spin-state transition. The high-spin Ni-Co3 O4 generate appropriate binding strength and enhance electron transfer between the Co centers with oxygen intermediates, thereby improving the catalytic activity of Ni-Co3 O4 for effective generating 1 O2 . In neutral conditions, 1×106  CFU mL-1 Gram-negative ESBL-producing Escherichia coli (E. coli) could be inactivated by Ni-Co3 O4 system within 5 min. Further antibacterial mechanisms indicate that 1 O2 can lead to cell membrane damage and DNA degradation so as to irreversible cell death. Additionally, the developed Ni-Co3 O4 system can effectively inactivate bacteria from wastewater and bioaerosols. This work provides an effective strategy for designing high-spin electrocatalysis to boost 1 O2 generation for disinfection process.


Assuntos
Desinfecção , Oxigênio Singlete , Escherichia coli , Hibridização de Ácido Nucleico , Hibridização Genética , Oxigênio
20.
J Neurosci ; 42(34): 6487-6505, 2022 08 24.
Artigo em Inglês | MEDLINE | ID: mdl-35896423

RESUMO

Retinal bipolar cells (BCs) compose the canonical vertical excitatory pathway that conveys photoreceptor output to inner retinal neurons. Although synaptic transmission from BC terminals is thought to rely almost exclusively on Ca2+ influx through voltage-gated Ca2+ (CaV) channels mediating L-type currents, the molecular identity of CaV channels in BCs is uncertain. Therefore, we combined molecular and functional analyses to determine the expression profiles of CaV α1, ß, and α2δ subunits in mouse rod bipolar (RB) cells, BCs from which the dynamics of synaptic transmission are relatively well-characterized. We found significant heterogeneity in CaV subunit expression within the RB population from mice of either sex, and significantly, we discovered that transmission from RB synapses was mediated by Ca2+ influx through P/Q-type (CaV2.1) and N-type (CaV2.2) conductances as well as the previously-described L-type (CaV1) and T-type (CaV3) conductances. Furthermore, we found both CaV1.3 and CaV1.4 proteins located near presynaptic ribbon-type active zones in RB axon terminals, indicating that the L-type conductance is mediated by multiple CaV1 subtypes. Similarly, CaV3 α1, ß, and α2δ subunits also appear to obey a "multisubtype" rule, i.e., we observed a combination of multiple subtypes, rather than a single subtype as previously thought, for each CaV subunit in individual cells.SIGNIFICANCE STATEMENT Bipolar cells (BCs) transmit photoreceptor output to inner retinal neurons. Although synaptic transmission from BC terminals is thought to rely almost exclusively on Ca2+ influx through L-type voltage-gated Ca2+ (CaV) channels, the molecular identity of CaV channels in BCs is uncertain. Here, we report unexpectedly high molecular diversity of CaV subunits in BCs. Transmission from rod bipolar (RB) cell synapses can be mediated by Ca2+ influx through P/Q-type (CaV2.1) and N-type (CaV2.2) conductances as well as the previously-described L-type (CaV1) and T-type (CaV3) conductances. Furthermore, CaV1, CaV3, ß, and α2δ subunits appear to obey a "multisubtype" rule, i.e., a combination of multiple subtypes for each subunit in individual cells, rather than a single subtype as previously thought.


Assuntos
Canais de Cálcio Tipo L , Sinapses , Animais , Cálcio/metabolismo , Canais de Cálcio Tipo L/genética , Canais de Cálcio Tipo L/metabolismo , Camundongos , Terminações Pré-Sinápticas/metabolismo , Retina/metabolismo , Sinapses/fisiologia , Transmissão Sináptica/fisiologia
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