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1.
Sci Total Environ ; 946: 174027, 2024 Jun 19.
Artículo en Inglés | MEDLINE | ID: mdl-38906297

RESUMEN

The global health implications of fine particulate matter (PM2.5) underscore the imperative need for research into its toxicity and chemical composition. In this study, zebrafish embryos exposed to the water-soluble components of PM2.5 from two cities (Harbin and Hangzhou) with differences in air quality, underwent microscopic examination to identify primary target organs. The Harbin PM2.5 induced dose-dependent organ malformation in zebrafish, indicating a higher level of toxicity than that of the Hangzhou sample. Harbin PM2.5 led to severe deformities such as pericardial edema and a high mortality rate, while the Hangzhou sample exhibited hepatotoxicity, causing delayed yolk sac absorption. The experimental determination of PM2.5 constituents was followed by the application of four algorithms for predictive toxicological assessment. The random forest algorithm correctly predicted each of the effect classes and showed the best performance, suggesting that zebrafish malformation rates were strongly correlated with water-soluble components of PM2.5. Feature selection identified the water-soluble ions F- and Cl- and metallic elements Al, K, Mn, and Be as potential key components affecting zebrafish development. This study provides new insights into the developmental toxicity of PM2.5 and offers a new approach for predicting and exploring the health effects of PM2.5.

2.
Adv Mater ; : e2404392, 2024 Jun 05.
Artículo en Inglés | MEDLINE | ID: mdl-38838201

RESUMEN

It is highly desired to develop a visual sensing system for ultrasensitive detection of colorless diclofenac (DCF), yet with a significant challenge. Herein, a novel dye-based photosensitization sensing system has been successfully developed for detecting DCF for the first time, in which the used dye eosin Y (DeY) can strongly absorb visible light and then be decolorized obviously by transferring photogenerated electrons to g-C3N4 nanosheets (CN), while the built single-atomic Co─N2O2 sites on CN by boron-oxygen connection can competitively adsorb DCF to impede the photosensitization decoloration of DeY. This system exhibits a broad detection range from 8 ng L-1 to 2 mg L-1 with 535 nm light, an exceptionally low detection limit (3.5 ng L-1), and remarkable selectivity. Through the time-resolved, in situ technologies, and theoretical calculations, the decolorization of DeY is attributed to the disruption of DeY's conjugated structure caused by the triplet excited state electron transfer from DeY to CN, meanwhile, the adsorbed oxygen facilitates the charge transfer process. The preferential adsorption of DCF mainly depends on the strong interactions between the as-constructed single-atom Co and Cl in DCF. This study opens an innovative light-driven sensing system by combining dye and single-atom metal/nanomaterial for visually intuitive detection of environmental pollutants.

3.
Chem Biodivers ; : e202400753, 2024 May 31.
Artículo en Inglés | MEDLINE | ID: mdl-38818648

RESUMEN

VEGFR-2 is a prominent therapeutic target in antitumor drug research to block tumor angiogenesis. This study focused on the synthesis and optimization of PROTACs based on the natural product rhein, resulting in the successful synthesis of 15 distinct molecules. In A549 cells, D9 exhibited remarkable antitumor efficacy with an IC50 of 5.88 ± 0.50 µM, which was 15-fold higher compared to rhein (IC50=88.45 ± 2.77 µM). An in-depth study of the effect of D9 on the degradation of VEGFR-2 revealed that D9 was able to induce the degradation of VEGFR-2 in A549 cells in a time-dependent manner. The observed effect was reversible, contingent upon the proteasome and ubiquitination system, and demonstrably linked to CRBN. Further experiments revealed that D9 induced apoptosis in A549 cells and led to cell cycle arrest in the G1 phase. Molecular docking simulations validated the binding mode of D9 to VEGFR, establishing the potential of D9 to bind to VEGFR-2 in its natural state. In summary, this study confirms the feasibility of natural product-bound PROTAC technology for the development of a new generation of VEGFR-2 degraders, offering a novel trajectory for the future development of pharmacological agents targeting VEGFR-2.

4.
Water Res ; 258: 121706, 2024 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-38761590

RESUMEN

Micro/nano-plastics (MNPs), as emerging persistent pollutants, are threatening freshwater ecosystems worldwide. Microalgae are important primary producers at the base of trophic level and susceptible to MNPs contamination, possibly resulting in further contamination in higher trophic levels and water quality. This study conducted a systematic review of 1071 observations from 63 publications, utilizing meta-analysis and subgroup analysis to investigate the toxicological effect patterns of MNPs parameters (size, concentration, and type) on microalgae. We also explored the potential eco-risks of certain specific MNPs parameters and subtle variations in the response of various microalgae taxa to MNPs. Results suggested that microplastics significantly inhibited microalgal photosynthesis, while nano-plastics induced more severe cell membrane damage and promoted toxin-release. Within a certain range of concentrations (0∼50 mg/L), rising MNPs concentration progressively inhibited microalgal growth and chlorophyll-a content, and progressively enhanced toxin-release. Among MNPs types, polyamide caused higher growth inhibition and more severe lipid peroxidation, and polystyrene induced more toxin-release, whereas polyethylene terephthalate and polymethyl methacrylate posed minimal effects on microalgae. Moreover, Bacillariophyta growth was inhibited most significantly, while Chlorophyta displayed strong tolerance and Cyanophyta possessed strong adaptive and exceptional resilience. Particularly, Komvophoron, Microcystis, Nostoc, Scenedesmus, and Gomphonema were more tolerant and might dominate freshwater microalgal communities under MNPs contamination. These results are crucial for acquiring the fate of freshwater microalgae under various MNPs contamination, identifying dominant microalgae, and reasonably assessing and managing involved eco-risks.


Asunto(s)
Agua Dulce , Microalgas , Contaminantes Químicos del Agua , Microalgas/efectos de los fármacos , Contaminantes Químicos del Agua/toxicidad , Microplásticos/toxicidad , Plásticos/toxicidad , Fotosíntesis/efectos de los fármacos
5.
Dalton Trans ; 53(17): 7315-7320, 2024 Apr 30.
Artículo en Inglés | MEDLINE | ID: mdl-38590209

RESUMEN

In recent years, organic-inorganic hybrid materials have demonstrated exceptional performance in nonlinear optics, attracting widespread attention. However, there are relatively few examples of coordination compounds synthesized with Cu as the metal center that exhibit excellent nonlinear optical properties. In this study, we successfully synthesized a pair of enantiomers named R/S-Cu2I2 by reacting chiral ligands with CuI. The crystal structure reveals a one-dimensional copper-iodide chain structure built by Cu2I2 clusters, and its ordered arrangement in space provides not only a strong second harmonic generation (SHG) signal (1.24 × KDP) but also a large birefringence (0.15@1064 nm). Under excitation at 395 nm, the crystals exhibit red fluorescence peaked at 675 nm. The CD spectra of R/S-Cu2I2 show a distinct mirror-symmetric Cotton effect, and their CPL signals are corresponding and opposite in the emission range, with a maximum glum of approximately ±2.5 × 10-3. Theoretical calculations using density functional theory were also carried out to enhance our understanding of the correlation between their structures and optical properties.

6.
Trials ; 25(1): 166, 2024 Mar 04.
Artículo en Inglés | MEDLINE | ID: mdl-38439027

RESUMEN

BACKGROUND: Endovascular thrombectomy (EVT) is a standard treatment for acute ischemic stroke (AIS) with large vessel occlusion. Hypertension and increased blood pressure variability within the first 24 h after successful reperfusion are related to a higher risk of symptomatic intracerebral hemorrhage and higher mortality. AIS patients might suffer from ischemia-reperfusion injury following reperfusion, especially within 24 h. Dexmedetomidine (DEX), a sedative commonly used in EVT, can stabilize hemodynamics by inhibiting the sympathetic nervous system and alleviate ischemia-reperfusion injury through anti-inflammatory and antioxidative properties. Postoperative prolonged sedation for 24 h with DEX might be a potential pharmacological approach to improve long-term prognosis after EVT. METHODS: This single-center, open-label, prospective, randomized controlled trial will include 368 patients. The ethics committee has approved the protocol. After successful reperfusion (modified thrombolysis in cerebral infarction scores 2b-3, indicating reperfusion of at least 50% of the affected vascular territory), participants are randomly assigned to the intervention or control group. In the intervention group, participants will receive 0.1~1.0 µg/kg/h DEX for 24 h. In the control group, participants will receive an equal dose of saline for 24 h. The primary outcome is the functional outcome at 90 days, measured with the categorical scale of the modified Rankin Scale, ranging from 0 (no symptoms) to 6 (death). The secondary outcome includes (1) the changes in stroke severity between admission and 24 h and 7 days after EVT, measured by the National Institute of Health Stroke Scale (ranging from 0 to 42, with higher scores indicating greater severity); (2) the changes in ischemic penumbra volume/infarct volume between admission and 7 days after EVT, measured by neuroimaging scan; (3) the length of ICU/hospital stay; and (4) adverse events and the all-cause mortality rate at 90 days. DISCUSSION: This randomized clinical trial is expected to verify the hypothesis that postoperative prolonged sedation with DEX after successful reperfusion may promote the long-term prognosis of patients with AIS and may reduce the related socio-economic burden. TRIAL REGISTRATION: ClinicalTrials.gov NCT04916197. Prospectively registered on 7 June 2021.


Asunto(s)
Dexmedetomidina , Accidente Cerebrovascular Isquémico , Daño por Reperfusión , Accidente Cerebrovascular , Humanos , Accidente Cerebrovascular Isquémico/diagnóstico , Accidente Cerebrovascular Isquémico/cirugía , Dexmedetomidina/efectos adversos , Estudios Prospectivos , Reperfusión , Trombectomía/efectos adversos , Accidente Cerebrovascular/diagnóstico , Accidente Cerebrovascular/terapia , Daño por Reperfusión/etiología , Daño por Reperfusión/prevención & control , Pronóstico , Ensayos Clínicos Controlados Aleatorios como Asunto
8.
CNS Neurosci Ther ; 30(2): e14365, 2024 02.
Artículo en Inglés | MEDLINE | ID: mdl-37485782

RESUMEN

AIMS: To verify the hypothesis that an enriched environment (EE) alleviates sleep deprivation-induced fear memory impairment by modulating the basal forebrain (BF) PIEZO1/calpain/autophagy pathway. METHODS: Eight-week-old male mice were housed in a closed, isolated environment (CE) or an EE, before 6-h total sleep deprivation. Changes in fear memory after sleep deprivation were observed using an inhibitory avoidance test. Alterations in BF PIEZO1/calpain/autophagy signaling were detected. The PIEZO1 agonist Yoda1 or inhibitor GsMTx4, the calpain inhibitor PD151746, and the autophagy inducer rapamycin or inhibitor 3-MA were injected into the bilateral BF to investigate the pathways involved in the memory-maintaining role of EE in sleep-deprived mice. RESULTS: Mice housed in EE performed better than CE mice in short- and long-term fear memory tests after sleep deprivation. Sleep deprivation resulted in increased PIEZO1 expression, full-length tropomyosin receptor kinase B (TrkB-FL) degradation, and autophagy, as reflected by increased LC3 II/I ratio, enhanced p62 degradation, increased TFEB expression and nuclear translocation, and decreased TFEB phosphorylation. These molecular changes were partially reversed by EE treatment. Microinjection of Yoda1 or rapamycin into the bilateral basal forebrain induced excessive autophagy and eliminated the cognition-protective effects of EE. Bilateral basal forebrain microinjection of GsMTx4, PD151746, or 3-MA mimicked the cognitive protective and autophagy inhibitory effects of EE in sleep-deprived mice. CONCLUSIONS: EE combats sleep deprivation-induced fear memory impairments by inhibiting the BF PIEZO1/calpain/autophagy pathway.


Asunto(s)
Acrilatos , Prosencéfalo Basal , Calpaína , Animales , Masculino , Ratones , Autofagia , Prosencéfalo Basal/metabolismo , Calpaína/metabolismo , Miedo , Trastornos de la Memoria/etiología , Trastornos de la Memoria/terapia , Transducción de Señal , Sirolimus/farmacología , Sirolimus/uso terapéutico , Privación de Sueño/complicaciones
9.
Nat Commun ; 14(1): 7993, 2023 Dec 02.
Artículo en Inglés | MEDLINE | ID: mdl-38042861

RESUMEN

Chemical reaction kinetics can be evaluated by probing dynamic changes of chemical substrates or physical phenomena accompanied during the reaction process. Chemiluminescence, a light emitting exoenergetic process, involves random reaction positions and kinetics in solution that are typically characterized by ensemble measurements with nonnegligible average effects. Chemiluminescent reaction dynamics at the single-molecule level remains elusive. Here we report direct imaging of single-molecule chemiluminescent reactions in solution and probing of their reaction dynamics under catalytic conditions. Double-substrate Michaelis-Menten type of catalytic kinetics is found to govern the single-molecule reaction dynamics in solution, and a heterogeneity is found among different catalyst particles and different catalytic sites on a single particle. We further show that single-molecule chemiluminescence imaging can be used to evaluate the thermodynamics of the catalytic system, resolving activation energy at the single-particle level. Our work provides fundamental insights into chemiluminescent reactions and offers an efficient approach for evaluating catalysts.

10.
Neurobiol Dis ; 189: 106350, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37952680

RESUMEN

The activation of the immune system and the onset of pro- and anti-inflammatory responses play crucial roles in the pathophysiological processes of ischaemic stroke (IS). CD4+ regulatory T (Treg) cells is the main immunosuppressive cell population that is studied in the context of peripheral tolerance, autoimmunity, and the development of chronic inflammatory diseases. In recent years, more studies have focused on immune modulation after IS, and Treg cells have been demonstrated to be essential in the remission of inflammation, nerve regeneration, and behavioural recovery. However, the exact effects of Treg cells in the context of IS remain controversial, with some studies suggesting a negative correlation with stroke outcomes. In this review, we aim to provide a comprehensive overview of the current understanding of Treg cell involvement in post-stroke homeostasis. We summarized the literature focusing on the temporal changes in Treg cell populations after IS, the mechanisms of Treg cell-mediated immunomodulation in the brain, and the potential of Treg cell-based therapies for treatment. The purposes of the current article are to address the importance of Treg cells and inspire more studies to help physicians, as well as scientists, understand the whole map of immune responses during IS.


Asunto(s)
Isquemia Encefálica , Accidente Cerebrovascular , Humanos , Linfocitos T Reguladores , Brazo , Homeostasis , Tolerancia Inmunológica
11.
Bioorg Med Chem ; 96: 117537, 2023 12 15.
Artículo en Inglés | MEDLINE | ID: mdl-37992440

RESUMEN

Proteolysis Targeting Chimeras (PROTAC) technology has emerged as a promising approach for targeted protein degradation. In this study, we focused on tyrosinase (TYR), a key enzyme involved in melanin synthesis and pigmentation. For this target, we designed and synthesized a series of PROTACs (D3-D9), employing Rhein as the target protein-ligand. Through some experimental tests, we made a significant discovery. Preliminary experimental results show that the most promising compound (D6) demonstrated the ability to degrade MITF and inhibit the expression and TYR in B16-F10 cells, effectively suppressing melanogenesis in zebrafish. Notably, at equivalent concentrations, the whitening effect of D6 surpassed that of its precursor Rhein and was even comparable to that of the well-established whitening agent, ß-arbutin. Validating experiments further revealed that the action of D6 was reliant on the E3 ligand, indicating its capacity to degrade TYR and MITF through the ubiquitination pathway. Whether D6 acts directly on TYR or MITF needs to be further explored. These compelling results underscore the tremendous whitening potential of D6, suggesting its suitability as a valuable lead for whitening agents and its potential to expand the range of whitening cosmetic products.


Asunto(s)
Melaninas , Melanoma Experimental , Animales , Quimera Dirigida a la Proteólisis , Pez Cebra , Ligandos , Monofenol Monooxigenasa , Proteolisis
12.
ACS Appl Bio Mater ; 6(6): 2303-2313, 2023 06 19.
Artículo en Inglés | MEDLINE | ID: mdl-37190932

RESUMEN

Since the nonspecificity and nonselectivity of traditional treatment models lead to the difficulty of cancer treatment, nanobased strategies are needed to fill in the gaps of current approaches. Herein, a tumor microenvironment (TME)-responsive chemo-photothermal treatment model was developed based on dihydroartemisinin (DHA)-loaded conjugated polymers (DHA@PLGA-PANI). The synthesized DHA@PLGA-PANI exhibited enhanced photothermal properties under mild-acidic conditions and thus triggered local heat at the tumor site. Meanwhile, these iron-doped conjugated polymers of PLGA-PANI were used as the source of Fe, and benefiting from the Fe-dependent cytotoxicity of DHA, the burst of free radicals could be generated in tumors. Therefore, the combination of TME-responsive chemo-photothermal therapy could achieve effective tumor efficacy.


Asunto(s)
Hipertermia Inducida , Neoplasias , Humanos , Polímeros , Terapia Fototérmica , Fototerapia , Neoplasias/tratamiento farmacológico , Microambiente Tumoral
13.
Adv Mater ; 35(21): e2300064, 2023 May.
Artículo en Inglés | MEDLINE | ID: mdl-36872578

RESUMEN

Solar-driven CO2 reduction by water with a Z-scheme heterojunction affords an avenue to access energy storage and to alleviate greenhouse gas (GHG) emissions, yet the separation of charge carriers and the integrative regulation of water oxidation and CO2 activation sites remain challenging. Here, a BiVO4 /g-C3 N4 (BVO/CN) Z-scheme heterojunction as such a prototype is constructed by spatially separated dual sites with CoOx clusters and imidazolium ionic liquids (IL) toward CO2 photoreduction. The optimized CoOx -BVO/CN-IL delivers an ≈80-fold CO production rate without H2 evolution compared with urea-C3 N4 counterpart, together with nearly stoichiometric O2 gas produced. Experimental results and DFT calculations unveil the cascade Z-scheme charge transfer and subsequently the prominent redox co-catalysis by CoOx and IL for holes-H2 O oxidation and electrons-CO2 reduction, respectively. Moreover, in situ µs-transient absorption spectra clearly show the function of each cocatalyst and quantitatively reveal that the resulting CoOx -BVO/CN-IL reaches up to the electron transfer efficiency of 36.4% for CO2 reduction, far beyond those for BVO/CN (4.0%) and urea-CN (0.8%), underlining an exceptional synergy of dual reaction sites engineering. This work provides deep insights and guidelines for the rational design of highly efficient Z-scheme heterojunctions with precise redox catalytic sites toward solar fuel production.

14.
Patient Prefer Adherence ; 17: 653-666, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36935941

RESUMEN

Background: Consistent and effective self-management is a major challenge for people with diabetes and long-term effects can be difficult to sustain despite the many interventions. Interventions often fail to take patients' perceptions of self-management into account from their perspective. Exploring the needs preferences and the influencing factors of self-management in patients can improve the effectiveness of self-management. Methods: This study used a mixed research approach, exploring patient needs and preferences through web crawl methods and using qualitative interviews to explore the logic of preferences. 1605 data were obtained from 4 online health communities through web crawlers. Data were coded using grounded theory to analyze self-management needs. The codes were also coded for frequency statistics and ranked to explain the self-management preferences. The second phase explained the logic of the ranked distribution of preferences through one-on-one interviews with 22 patients. Results: This study summarized six self-management needs of people with diabetes through web crawler data, among which medication management and conflict between disease and daily life were the most important concerns of patients. The reasons why patients are particularly concerned about these two needs were explored through qualitative interviews, and it was found that patients' concerns about medication were mainly due to the following three aspects: the effect of drugs is direct and obvious, medication use makes life less complicated, and progressive side effects. The patients' concerns about the conflict between disease and daily life are often caused by the following three aspects: diabetes impacts social roles, disease complicates life, and reducing the impact of the disease on life. Conclusion: The self-management needs of Chinese diabetics have six themes. Medication management, conflict between disease and daily life, diet, diabetes knowledge, blood glucose monitoring and exerciseIn order of frequency of mention and possible preference: medication management, conflict between disease and daily life were the most frequent needs, while diet, knowledge about diabetes, blood glucose monitoring and exercise were their least frequent needs.Understanding the individual's perception and understanding of diabetes self-management and the expression of the patient's daily life situations can guide the medical team to optimize collaboration on personalized care plans.

15.
J Med Internet Res ; 25: e39325, 2023 02 02.
Artículo en Inglés | MEDLINE | ID: mdl-36729569

RESUMEN

BACKGROUND: The diabetes disease burden in China is heavy, and medical standards such as diabetes guidelines are the core reference guidelines for diabetes management for health care providers and patients. However, patients' guideline compliance is too low, which correlates with the gap between guidelines and patients' self-management needs. Incorporating patient needs into the guideline development would reduce this gap. OBJECTIVE: We sought to capture the needs of patients with diabetes for self-management in everyday situations and to clarify the contradictions and misalignments between medical standards, such as guidelines, and patient needs. METHODS: This study collected crawler-based data from 4 online health communities. We selected 1605 text records collected from Chinese patients with diabetes between March 2020 and July 2020 for analysis. The text analysis applied grounded theory to separate issues that concerned patients into 3 themes, 7 subthemes, and 25 entries. RESULTS: Altogether, 69.03% (1108/1605) of texts were related to issues concerning disease treatment (theme B) and mainly inquired about medication use (B2 and B3; 686/1108, 61.91%), including medication choice, change in medication administration, side effects, and postmedication effects. In addition, 222 (N=1605, 13.8%) texts (theme A) concerned the explanation of disease etiology and knowledge of diabetes, and 275 (N=1605, 17.1%) texts (theme C) discussed lifestyle changes and various restrictions on life brought about by the disease. CONCLUSIONS: Our findings suggest an urgent need to improve diabetes health education and guideline development strategies and to develop health management strategies from a patient perspective to bridge the misalignment between patient needs and current medical standards.


Asunto(s)
Diabetes Mellitus Tipo 2 , Envío de Mensajes de Texto , Humanos , Diabetes Mellitus Tipo 2/terapia , Investigación Cualitativa , Cooperación del Paciente , Estilo de Vida
16.
Adv Mater ; 35(15): e2211575, 2023 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-36680460

RESUMEN

Ultrasensitively selective detection of trace polycyclic aromatic hydrocarbons (PAHs) like phenanthrene (PHE) is critical but remains challenging. Herein, atomically dispersed Zn sites on g-C3 N4 nanosheets (sZn-CN) are constructed by thermal polymerization of a Zn-cyanuric acid-melamine supramolecular precursor for the fluorescence detection of PHE. A high amount (1.6 wt%) of sZn is grafted in the cave of CN with one N vacancy in the form of unique Zn(II)N5 coordination. The optimized sZn-CN achieves a wide detection range (1 ng L-1 to 5 mg L-1 ), ultralow detection limit (0.35 ng L-1 , with 5-order magnitude improvement over CN), and ultrahigh selectivity toward PHE even among typical PAHs based on the built PHE-CN dual ratiometric fluorescence method. By means of in situ Fourier transform infrared spectroscopy, time-resolved absorption and fluorescence spectroscopy, and theoretical calculations, the resulting superior detection performance is attributed to the favorable selective adsorption of PHE on as-constructed atomic Zn(II)N5 sites via the ionic cation-π interactions (Znδ+ C2 δ- type), and the fluorescence quenching is dominated by the inner filter effect (IFE) from the multilayer adsorption of PHE at low concentrations, while it is done by the protruded photogenerated electron-transfer process, as well as IFE from the monolayer adsorption of PHE at ultralow concentration.

17.
Front Neurosci ; 16: 877937, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35685776

RESUMEN

Ischemic stroke (IS) is among the top prevalent neurologic disorders globally today. Risk factors such as hypertension, diabetes, and aging, contribute to the development of IS, and patients with these risk factors face heavier therapeutic burden and worse prognosis. Microbiota-gut-brain axis describes the crosstalk between the gut flora, intestine, and center nervous system, which conduct homeostatic effects through the bacterial metabolites, the regulation of immune activity, also the contact with enteric nerve ends and vagus nerve. Nowadays, more studies have paid attention to the important roles that microbiota-gut-brain axis played in the risk factors of IS. In the current article, we will review the recent works focusing on the bi-directional impacts of gut dysbiosis and the pathogenic process of IS-related risk factors, for the purpose to summarize some novel findings in this area, and try to understand how probiotics could limit the development of IS via different strategies.

18.
Nanoscale ; 14(22): 8041-8049, 2022 Jun 09.
Artículo en Inglés | MEDLINE | ID: mdl-35622376

RESUMEN

Developing efficient Z-scheme heterojunctions with wide visible-light responsive perylene diimide (PDI) is highly desired for CO2 conversion, while the effective charge transfer and separation are crucial. Herein, TiO2-modulated tetra(4-carboxyphenyl)porphyrin/perylene diimide (T-TP/PDI) organic nano-heterojunctions have been fabricated for CO2 reduction, in which TP and PDI are first assembled via π-π interactions between their similar 2D conjugate structures, and then the TiO2 nanoparticles (ca. 10 nm) are anchored as an energy platform through the carboxyl groups on TP. The optimal one exhibits a ∼10-fold enhancement in photocatalytic activity compared with the pristine PDI. Based on the time-resolved surface photovoltage responses, electron paramagnetic resonance signals, in situ diffuse reflectance infrared Fourier transform spectra and the amount evaluation of H2O2 as the water-oxidation intermediate, it is suggested that the exceptional photoactivity be ascribed to the accelerated charge transfer and separation resulting from the constructed Z-scheme nano-heterojunctions with intimate interfacial interactions and the introduced energy platform TiO2 oriented towards largely inhibiting the type-II charge transfer pathway. This work diversifies the strategies for constructing efficient organic Z-scheme heterojunctions, and provides insight into interface correlation among components.

19.
Angew Chem Int Ed Engl ; 61(14): e202200187, 2022 03 28.
Artículo en Inglés | MEDLINE | ID: mdl-35084097

RESUMEN

Classical electrochemical characterization tools cannot avoid averaging between the active reaction sites and their support, thus obscuring their intrinsic roles. Single-molecule electrochemical techniques are thus in high demand. Here, we demonstrate super-resolution imaging of Ru(bpy)32+ based reactions on Au plates using single-molecule electrochemiluminescence microscopy. By converting electrochemical signals into optical signals, we manage to achieve the ultimate sensitivity of single-entity chemistry, that is directly resolving the single photons from individual electrochemical reactions. High spatial resolution, up to 37 nm, further enables mapping Au chemical activity and the reaction kinetics. The spatiotemporally resolved dynamic structure-activity relationship on Au plates shows that the restructuring of catalysts plays an important role in determining the reactivity. Our approach may lead to gaining new insights towards evaluating and designing electrocatalytic systems.


Asunto(s)
Oro , Mediciones Luminiscentes , Técnicas Electroquímicas/métodos , Oro/química , Mediciones Luminiscentes/métodos , Microscopía , Imagen Individual de Molécula
20.
Oncol Rep ; 46(4)2021 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-34368877

RESUMEN

Following the publication of this paper, it was drawn to the Editors' attention by a concerned reader that certain of the flow cytometric data shown in Fig. 3, and western blotting assay data shown in Fig. 6F, were strikingly similar to data appearing in different form in other articles by different authors. Owing to the fact that the contentious data in the above article had already been published elsewhere, or were already under consideration for publication, prior to its submission to Oncology Reports, the Editor has decided that this paper should be retracted from the Journal. The authors were asked for an explanation to account for these concerns, but the Editorial Office did not receive any reply. The Editor apologizes to the readership for any inconvenience caused. [the original article was published in Oncology Reports 36: 471­479, 2016; DOI: 10.3892/or.2016.4824].

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