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1.
Stem Cells ; 2024 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-38655883

RESUMO

Fully grown oocytes have the natural ability to transform two terminally differentiated gametes into a totipotent zygote representing acquisition of totipotency. This process wholly depends on maternal-effect factors (MFs). MFs stored in the eggs are therefore likely to be able to induce cellular reprogramming to a totipotency state. Here we report the generation of totipotent-like stem cells from mESCs using 4MFs Hsf1, Zar1, Padi6 and Npm2, designated as MFiTLSCs. MFiTLSCs exhibited unique and inherent capability to differentiate into embryonic and extraembryonic derivatives. Transcriptomic analysis revealed that MFiTLSCs are enriched with 2-cell-specific genes that appear to synergistically induce a transcriptional repressive state, in that parental genomes are remodelled to a poised transcriptional repression state while totipotency is established following fertilization. This method to derive MFiTLSCs could help advance understanding of fate determinations of totipotent stem cells in a physiological context and establish a foundation for development of oocyte biology-based reprogramming technology.

2.
J Magn Reson Imaging ; 59(3): 825-834, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37338016

RESUMO

BACKGROUND: Few studies assessed myocardial inflammation using Cardiovascular Magnetic Resonance Imaging in Kawasaki disease (KD) patients. PURPOSE: To quantify myocardial edema in KD patients using T2 mapping and explore the independent predictors of T2 values. STUDY TYPE: Prospective. SUBJECTS: Ninety KD patients including 40 in acute phase (26 males, 65.0%) and 50 in chronic phase (34 males, 68.0%). Thirty-one healthy volunteers (21 males, 70.0%). FIELD STRENGTH/SEQUENCE: 3.0 T T2-weighted Turbo Spin Echo-Short Time of Inversion Recovery sequence, True fast imaging with steady precession flash sequence and fast low-angle shot 3D spoiled gradient echo sequence. ASSESSMENT: T2 values were compared among KD groups and controls. STATISTICAL TEST: Student's t test and Fisher's exact test; One-way analysis of variance; Pearson correlation analysis; Receiver operating curve analysis; Multivariable linear regression. RESULTS: Global T2 value of KD patients in acute phase was the highest, followed by those of chronic-phase patients and controls (38.83 ± 2.41 msec vs. 37.55 ± 2.28 msec vs. 36.05 ± 1.64 msec). Regional T2 values showed a same trend. There were no significant differences in global and regional T2 values between KD patients with and without coronary artery (CA) dilation, no matter in acute or chronic phase (all KD patients: P = 0.51, 0.51, 0.53, 0.72; acute KD: P = 0.61, 0.37, 0.33, 0.83; chronic KD: P = 0.65, 0.79, 0.62, 0.79). No significant difference was observed in global T2 values between KD patients with Z score > 5.0 and 2.0 < Z score ≤ 5.0 (P = 0.65). Multivariate analysis demonstrated that stage of disease (ß = -0.123) and heart rate (ß = 0.280) were independently associated with global T2 values. DATA CONCLUSION: The degree of myocardial edema was more severe in acute-phase than in chronic-phase KD patients. Myocardial edema persists in patients regardless of the existence or degree of CA dilation. EVIDENCE LEVEL: 2 TECHNICAL EFFICACY: Stage 2.


Assuntos
Síndrome de Linfonodos Mucocutâneos , Masculino , Criança , Humanos , Estudos Prospectivos , Miocárdio/patologia , Imageamento por Ressonância Magnética/métodos , Edema
3.
Chemphyschem ; 25(5): e202300610, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38264930

RESUMO

Rechargeable zinc-air batteries (RZABs) are an ideal substitute for energy storage, but the short cycle longevity during long-term charge/discharge operation is one of the bottleneck factors that seriously restrict commercial application. Herein, the FeCo alloy/N, S co-doped carbon aerogel (NSCA/FeCo) were prepared as catalysts of cathode for RZABs. We investigated the polarization and impedance on long-term cycles during the battery operation to explore the attenuation mechanism. The results indicated that the roundtrip efficiency of batteries during charge/discharge cycles reduced fast initially and then slow. Besides, the comparative experiment was tested through the replacement of a new electrolyte and a zinc sheet. It is manifested that the failure of the battery is mainly due to the attenuation of the air cathode performance. Therefore, to further disclose the influencing factors and internal mechanisms of air cathode performance degradation, we conducted a series of characterization and testing, including the hydrophilicity, surface morphology, elemental composition, and electrochemical performance of three-electrode systems at different cycle times. This work not only provides a theoretical basis for deeply comprehending the attenuation mechanism of the cathode but also serves a reference for the material design and operating condition optimization of RZABs.

4.
BMC Cardiovasc Disord ; 24(1): 113, 2024 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-38365597

RESUMO

BACKGROUND: Patients with diabetes mellitus (DM) caused by obesity have increased in recent years. The impact of obesity on long-term outcomes in patients undergoing percutaneous coronary intervention (PCI) with or without DM remains unclear. METHODS: We retrospectively analysed data from 1918 patients who underwent PCI. Patients were categorized into four groups based on body mass index (BMI, normal weight: BMI < 25 kg/m2; overweight and obese: BMI ≥ 25 kg/m2) and DM status (presence or absence). The primary endpoint was the occurrence of major adverse cardiac and cerebrovascular events (MACCE; defined as all-cause death, myocardial infarction, stroke, and unplanned repeat revascularization). RESULTS: During a median follow-up of 7.0 years, no significant differences in MACCE, myocardial infarction, or stroke were observed among the four groups. Overweight and obese individuals exhibited lower all-cause mortality rates compared with normal-weight patients (without DM: hazard ratio [HR]: 0.54, 95% confidence interval [CI]: 0.37 to 0.78; with DM: HR: 0.57, 95% CI: 0.38 to 0.86). In non-diabetic patients, the overweight and obese group demonstrated a higher risk of unplanned repeat revascularization than the normal-weight group (HR:1.23, 95% CI:1.03 to 1.46). After multivariable adjustment, overweight and obesity were not significantly associated with MACCE, all-cause death, myocardial infarction, stroke, or unplanned repeat revascularization in patients with and without diabetes undergoing PCI. CONCLUSION: Overweight and obesity did not demonstrate a significant protective effect on long-term outcomes in patients with and without diabetes undergoing PCI.


Assuntos
Doença da Artéria Coronariana , Diabetes Mellitus , Infarto do Miocárdio , Intervenção Coronária Percutânea , Acidente Vascular Cerebral , Humanos , Sobrepeso , Estudos Retrospectivos , Índice de Massa Corporal , Intervenção Coronária Percutânea/efeitos adversos , Diabetes Mellitus/diagnóstico , Diabetes Mellitus/epidemiologia , Infarto do Miocárdio/etiologia , Obesidade/complicações , Obesidade/diagnóstico , Acidente Vascular Cerebral/diagnóstico , Acidente Vascular Cerebral/epidemiologia , Acidente Vascular Cerebral/complicações , Resultado do Tratamento , Doença da Artéria Coronariana/diagnóstico por imagem , Doença da Artéria Coronariana/terapia , Doença da Artéria Coronariana/complicações
5.
Angew Chem Int Ed Engl ; 63(9): e202314383, 2024 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-38216536

RESUMO

Directional organic transformation via a green, sustainable catalytic reaction has attracted a lot of attention. Herein, we report a photoelectrochemical approach for highly selective epoxidation of alkenes in a salt solution using Co2 (OH)3 Cl (CoOCl) as a bridge of photo-generated charge, where the lattice Cl- of CoOCl can be oxidized to generate HClO by the photo-generated holes of BiVO4 photoanode and be spontaneously recovered by Cl- of a salt solution, which then oxidizes the alkenes into the corresponding epoxides. As a result, a series of water-soluble alkenes, including 4-vinylbenzenesulfonic acid sodium, 2-methyl-2-propene-1-sulfonic acid sodium, and 3-methyl-3-buten-1-ol can be epoxidized with near 100 % conversion rate and selectivity. Through further inserting a MoOx protection layer between BiVO4 and CoOCl, the stability of CoOCl-MoOx /BiVO4 can be maintained for at least 120 hours. This work opens an avenue for solar-driven organic epoxidation with a possibility of on-site reaction around the abundant ocean.

6.
Bioinformatics ; 38(5): 1477-1479, 2022 02 07.
Artigo em Inglês | MEDLINE | ID: mdl-34788369

RESUMO

SUMMARY: DeepKG is an end-to-end deep learning-based workflow that helps researchers automatically mine valuable knowledge in biomedical literature. Users can utilize it to establish customized knowledge graphs in specified domains, thus facilitating in-depth understanding on disease mechanisms and applications on drug repurposing and clinical research. To improve the performance of DeepKG, a cascaded hybrid information extraction framework is developed for training model of 3-tuple extraction, and a novel AutoML-based knowledge representation algorithm (AutoTransX) is proposed for knowledge representation and inference. The system has been deployed in dozens of hospitals and extensive experiments strongly evidence the effectiveness. In the context of 144 900 COVID-19 scholarly full-text literature, DeepKG generates a high-quality knowledge graph with 7980 entities and 43 760 3-tuples, a candidate drug list, and relevant animal experimental studies are being carried out. To accelerate more studies, we make DeepKG publicly available and provide an online tool including the data of 3-tuples, potential drug list, question answering system, visualization platform. AVAILABILITY AND IMPLEMENTATION: All the results are publicly available at the website (http://covidkg.ai/). SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.


Assuntos
COVID-19 , Aprendizado Profundo , Animais , Reconhecimento Automatizado de Padrão , Fluxo de Trabalho , Algoritmos
7.
BMC Microbiol ; 23(1): 363, 2023 Nov 24.
Artigo em Inglês | MEDLINE | ID: mdl-38001408

RESUMO

OBJECTIVE: The gut microbial composition has been linked to metabolic and autoimmune diseases, including arthritis. However, there is a dearth of knowledge on the gut bacteriome, mycobiome, and virome in patients with gouty arthritis (GA). METHODS: We conducted a comprehensive analysis of the multi-kingdom gut microbiome of 26 GA patients and 28 healthy controls, using whole-metagenome shotgun sequencing of their stool samples. RESULTS: Profound alterations were observed in the gut bacteriome, mycobiome, and virome of GA patients. We identified 1,117 differentially abundant bacterial species, 23 fungal species, and 4,115 viral operational taxonomic units (vOTUs). GA-enriched bacteria included Escherichia coli_D GENOME144544, Bifidobacterium infantis GENOME095938, Blautia_A wexlerae GENOME096067, and Klebsiella pneumoniae GENOME147598, while control-enriched bacteria comprised Faecalibacterium prausnitzii_G GENOME147678, Agathobacter rectalis GENOME143712, and Bacteroides_A plebeius_A GENOME239725. GA-enriched fungi included opportunistic pathogens like Cryptococcus neoformans GCA_011057565, Candida parapsilosis GCA_000182765, and Malassezia spp., while control-enriched fungi featured several Hortaea werneckii subclades and Aspergillus fumigatus GCA_000002655. GA-enriched vOTUs mainly attributed to Siphoviridae, Myoviridae, Podoviridae, and Microviridae, whereas control-enriched vOTUs spanned 13 families, including Siphoviridae, Myoviridae, Podoviridae, Quimbyviridae, Phycodnaviridae, and crAss-like. A co-abundance network revealed intricate interactions among these multi-kingdom signatures, signifying their collective influence on the disease. Furthermore, these microbial signatures demonstrated the potential to effectively discriminate between patients and controls, highlighting their diagnostic utility. CONCLUSIONS: This study yields crucial insights into the characteristics of the GA microbiota that may inform future mechanistic and therapeutic investigations.


Assuntos
Artrite Gotosa , Microbioma Gastrointestinal , Microbiota , Micobioma , Humanos , População do Leste Asiático , Bactérias/genética
8.
Opt Express ; 31(4): 6659-6674, 2023 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-36823917

RESUMO

This paper proposes a 3-dimensional (3D) carrier-less amplitude and phase modulation (CAP) based on a pyramid constellation design encryption scheme for 7-core fiber in passive optical network (PON). The chaos sequences generated by the 4D hyperchaotic system are applied to produce the masking factor, and the pyramid Rubik's cube rotation rules are used to flip and rotate the constellation points. To verify the performance of the proposed 3D CAP-PON system, 25.5Gb/s encrypted Pyraminx-3D-CAP-16 signal transmission over 2 km 7-core fiber is experimentally demonstrated. Compared with the traditional 3D-CAP-16 signal, the proposed Pyraminx-3D-CAP-16 signal achieves a sensitivity gain of 0.5 dB under the limit of hard decision forward error correction (HD-FEC) 3.8 × 10-3. Compared with the Pyraminx-3D-CAP-16 signal, the encrypted Pyraminx-3D-CAP-16 signal has little difference from that before encryption, which has a great application prospect in the physical layer security enhancement of the 3D-CAP-PON system.

9.
Cardiovasc Diabetol ; 22(1): 171, 2023 07 07.
Artigo em Inglês | MEDLINE | ID: mdl-37420232

RESUMO

BACKGROUND: The triglyceride-glucose (TyG) index has been demonstrated to be a reliable surrogate marker of insulin resistance (IR) and an effective predictive index of cardiovascular (CV) disease risk. However, its long-term prognostic value in patients with chronic heart failure (CHF) remains uncertain. METHODS: A total of 6697 consecutive patients with CHF were enrolled in this study. Patients were divided into tertiles according to their TyG index. The incidence of primary outcomes, including all-cause death and CV death, was recorded. The TyG index was calculated as ln [fasting triglycerides (mg/dL) × fasting blood glucose (mg/dL)/2]. RESULTS: During a median follow-up of 3.9 years, a total of 2158 (32.2%) all-cause deaths and 1305 (19.5%) CV deaths were documented. The incidence of primary events from the lowest to the highest TyG index tertiles were 50.61, 64.64, and 92.25 per 1000 person-years for all-cause death and 29.05, 39.40, and 57.21 per 1000 person-years for CV death. The multivariate Cox hazards regression analysis revealed hazard ratios for all-cause and CV deaths of 1.84 (95% CI 1.61-2.10; P for trend < 0.001) and 1.94 (95% CI 1.63-2.30; P for trend < 0.001) when the highest and lowest TyG index tertiles were compared. In addition, the predictive ability of the TyG index against all-cause death was more prominent among patients with metabolic syndrome and those with heart failure with preserved ejection fraction phenotype (both P for interaction < 0.05). Furthermore, adding the TyG index to the established model for all-cause death improved the C­statistic value (0.710 for the established model vs. 0.723 for the established model + TyG index, P < 0.01), the integrated discrimination improvement value (0.011, P < 0.01), the net reclassification improvement value (0.273, P < 0.01), and the clinical net benefit (probability range, 0.07-0.36). CONCLUSIONS: The TyG index was significantly associated with the risk of mortality, suggesting that it may be a reliable and valuable predictor for risk stratification and an effective prognostic indicator in patients with CHF.


Assuntos
Glucose , Insuficiência Cardíaca , Humanos , Fatores de Risco , Glicemia/metabolismo , Medição de Risco , Estudos Retrospectivos , Triglicerídeos , Biomarcadores , China/epidemiologia , Doença Crônica , Insuficiência Cardíaca/diagnóstico
10.
Chemistry ; 29(67): e202302883, 2023 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-37803409

RESUMO

A practical and efficient propargylboration of ketones is presented using general allenylboronic acid pinacol esters (allenyl-Bpins) without a catalyst. This reaction is triggered by in-situ activation of stable allenyl-Bpins through the sequential addition of 1.25 equiv. of n BuLi and the prerequisite 2.0 equiv. of TFAA. Under the optimized reaction conditions, the versatile trisubstituted allenyl-Bpins react with various ketones smoothly to afford a wide range of tert-homopropargyl alcohols bearing vicinal stereocenters in high yields with good to excellent diastereoselectivities. Furthermore, propargylboration of ketones with chiral trisubstituted allenyl-Bpins allows for the asymmetric synthesis of chiral tert-homopropargyl alcohols with a full chirality transfer.

11.
Langmuir ; 2023 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-36625757

RESUMO

Transition metal phosphides with excellent performance are one of the effective alternatives to noble metal catalysts in overall water splitting. In this paper, the Fe-NiCoP-MoO3 composite was prepared by a facile synthesis as the bifunctional electrocatalyst. Fe-NiCoP-MoO3 achieves an operating current density of 10 mA/cm2 at a low overpotential of 65 mV for hydrogen evolution reaction and drives an operating current density of 50 mA/cm2 at only 293 mV for oxygen evolution reaction. Significantly, Fe-NiCoP-MoO3 was employed as the anode and cathode for overall water splitting, which only requires a cell voltage of 1.586 V to reach 10 mA/cm2 as well as shows excellent stability. The electrocatalytic activity of Fe-NiCoP-MoO3 exceeds most of the recently reported typical bifunctional electrocatalysts. This may be due to the coupling effect between the polymetallic phosphides. In addition, heterogeneous catalysts generally expose more active sites than homogeneous catalysts. In addition, replacing MoO3 with WO3 and VO3 can also improve the performance of Fe-NiCoP. This work provides an idea for the modification of phosphides.

12.
Org Biomol Chem ; 21(16): 3355-3359, 2023 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-37038891

RESUMO

A simple and novel Pd-catalysed cross-coupling reaction of allenylic carbonates with different gem-diborylalkanes was developed. Under mild reaction conditions, synthetically useful and versatile isoprenylboronates could be obtained selectively in moderate to high yields. Furthermore, the utility of the novel isoprenylboronate is demonstrated through isoprenylboration and homologation.

13.
Ren Fail ; 45(1): 2237124, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37482915

RESUMO

BACKGROUND: The treatment of refractory nephrotic syndrome (RNS) is full of challenges and the role of rituximab (RTX) is not well-established, thus this study aims to demonstrate the role of RTX in RNS. METHODS: This was a multicenter retrospective study of all adult patients receiving RTX for RNS. Patients enrolled were divided into two groups according to pathological pattern: 20 patients as a group of podocytopathy (including minimal change disease [MCD] and focal and segmental glomerulosclerosis [FSGS]), and 26 patients as membranous nephropathy (MN) group. The remission rate, relapse rate, adverse effects, and predictors of remission were analyzed. RESULTS: A total of 75 patients received RTX for RNS and 48 were available for analysis after exclusion criteria. No significant difference in the remission rate at 6 or 12 months was observed between the MCD/FSGS and MN cases (p > 0.05). The median duration of the first complete remission (CR) was 1 month in the podocytopathy group and 12.5 months in the MN group. Three relapses were associated with infection as the ultimate outcome, and 6 out of 48 remained refractory representing a response rate of 87.5% in RNS. Clinical predictors of cumulative CR were estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m2 and mean arterial pressure (MAP) ≤103 mmHg at the beginning of therapy in patients with MN. No serious adverse effects were reported. CONCLUSIONS: RTX appears to be effective in RNS across various clinical and pathological subtypes, exhibiting a low relapse rate and minimal significant side effects in the majority of patients.


Assuntos
Glomerulonefrite Membranosa , Glomerulosclerose Segmentar e Focal , Nefrose Lipoide , Síndrome Nefrótica , Humanos , Adulto , Rituximab/efeitos adversos , Estudos Retrospectivos , Glomerulosclerose Segmentar e Focal/complicações , Glomerulosclerose Segmentar e Focal/tratamento farmacológico , Síndrome Nefrótica/tratamento farmacológico , Resultado do Tratamento , Nefrose Lipoide/tratamento farmacológico , Glomerulonefrite Membranosa/tratamento farmacológico , Recidiva , Doença Crônica , Imunossupressores/uso terapêutico
14.
Nano Lett ; 22(9): 3678-3684, 2022 05 11.
Artigo em Inglês | MEDLINE | ID: mdl-35442043

RESUMO

Inspired by electronic transistors, electric field gating has been adopted to manipulate ionic currents of smart nanofluidic devices. Here, we report a PNP nanofluidic bipolar junction transistor (nBJT) consisting of one polyaniline (PANI) layer sandwiched between two polyethylene terephthalate (PET) nanoporous membranes. The PNP nBJT exhibits three different responses of currents (quasi-linear, rectification, and sigmoid) due to the counterbalance between surface charge distribution and base voltage applied in the nanofluidic channels; thus, they can be switched by base voltage. Four operating modes (cutoff, active, saturation, and breakdown mode) occur in the collector response currents. Under optimal conditions, the PNP nBJT exhibits an average current gain of up to 95 in 100 mM KCl solution at a low base voltage of 0.2 V. The present nBJT is promising for fabrication of nanofluidic devices with logical-control functions for analysis of single molecules.


Assuntos
Nanoporos , Nanotecnologia , Transporte de Íons , Íons , Transistores Eletrônicos
15.
Int Heart J ; 64(4): 732-740, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37518354

RESUMO

To investigate the possible effect of FoxO on coxsackievirus B3 (CVB3) -induced cardiomyocyte inflammation and apoptosis via modulation of the TLR4/NF-κB signaling pathway.Viral myocarditis (VMC) models were establied via CVB3 infection both in vivo and in vitro. Western blotting was adopted to detect FoxO1 and TLR4 expressions in myocardial tissues and cells. Cardiomyocytes of suckling mouse were divided into the control, CVB3, CVB3 + pcDNA, CVB3 + pcDNA-FoxO1, CVB3 + TLR4 siRNA, and CVB3 + pcDNA-FoxO1 + TLR4 siRNA groups. Flow cytometry was employed to evaluate cell apoptosis. The expressions of inflammatory factors including TNF-α, IL-1ß, and IL-6 were detected via quantitative reverse transcriptase polymerase chain reaction and enzyme-linked immunosorbent assay. Then, TLR4/NF-κB pathway-related proteins were determined via Western blotting.VMC mice had increased FoxO1 and TLR4 expressions in myocardial tissues. Cardiomyocytes with CVB3 infection also had upregulated protein expressions of p-FoxO1/FoxO1 and TLR4. Compared with those in the control group, the cardiomyocytes in the CVB3 group were increased in LDH and CK-MB levels, cell apoptosis rate and inflammatory factors (TNF-α, IL-1ß and IL-6), as well as protein expressions of TLR4 and p-p65/p65. Compared with those in the CVB3 group, the cardiomyocytes in the CVB3 + pcDNA-FoxO1 group were further upregulated whereas those in the CVB3 +TLR4 siRNA group were downregulated in the aforementioned indicators. Furthermore, TLR4 siRNA can reverse the effect of pcDNA-FoxO1 on the aggravation of cardiomyocyte injury induced by CVB3 infection.FoxO1 can upregulate the TLR4/NF-κB signaling pathway to promote cardiomyocyte apoptosis and inflammatory injury in CVB3-induced VMC.


Assuntos
Infecções por Coxsackievirus , Miocardite , Camundongos , Animais , Miocardite/metabolismo , Miócitos Cardíacos/metabolismo , NF-kappa B/metabolismo , Fator de Necrose Tumoral alfa/metabolismo , Interleucina-6/metabolismo , Receptor 4 Toll-Like/metabolismo , Inflamação/metabolismo , Transdução de Sinais , Apoptose , Infecções por Coxsackievirus/metabolismo , RNA Interferente Pequeno
16.
J Environ Sci (China) ; 125: 319-331, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36375917

RESUMO

Oxidation-absorption technology is a key step for NOx removal from low-temperature gas. Under the condition of low O3 concentration (O3/NO molar ratio = 0.6), F-TiO2 (F-TiO2), which is cheap and environmentally friendly, has been prepared as ozonation catalysts for NO oxidation. Catalytic activity tests performed at 120°C showed that the NO oxidation efficiency of F-TiO2 samples was higher than that of TiO2 (about 43.7%), and the NO oxidation efficiency of F-TiO2-0.15 was the highest, which was 65.3%. Combined with physicochemical characteristics of catalysts and the analysis of active species, it was found that there was a synergistic effect between F sites and oxygen vacancies on F-TiO2, which could accelerate the transformation of monomolecular O3 into multi-molecule singlet oxygen (1O2), thus promoting the selective oxidation of NO to NO2. The oxidation reaction of NO on F-TiO2-0.15 follows the Eley-Rideal mechanism, that is, gaseous NO reacts with adsorbed O3 and finally form NO2.


Assuntos
Dióxido de Nitrogênio , Oxigênio , Catálise , Oxirredução , Oxigênio/química , Titânio/química , Ozônio/química , Óxido Nítrico/química
17.
J Am Chem Soc ; 144(22): 9576-9585, 2022 06 08.
Artigo em Inglês | MEDLINE | ID: mdl-35623060

RESUMO

Photocatalytic reduction of CO2 with light and H2O to form CH3OH is a promising route to mitigate carbon emissions and climate changes. Although semiconducting metal oxides are potential photocatalysts for this reaction, low photon efficiency and leaching of environmentally unfriendly toxic metals limit their applicability. Here, we report metal-free, core-shell photocatalysts consisting of graphitic carbon nitride (g-C3N4, CN) covalently linked to melamine-resorcinol-formaldehyde (MRF) microsphere polymers for this reaction. Covalent linkage enabled efficient separation of photo-generated carriers and photocatalysis. Using 100 mg of a photocatalyst containing 15 wt % CN, a CH3OH yield of 0.99 µmol·h-1 was achieved at a reaction temperature of 80 °C and 0.5 MPa with external quantum efficiencies ranging from 5.5% at 380 nm to 1.7% at 550 nm. The yield was about 20 and 10 times higher than that of its components CN and MRF, respectively. Characterization with X-ray photoelectron spectroscopy, transmission electron microscopy, and bulk and surface elemental analyses supported the formation of a core-shell structure and the charge transfer in the C-N bond at the CN-MRF interface between the methoxy group in the 2,4-dihydroxylmethyl-1,3-diphenol part of MRF and the terminal amino groups in CN. This enhanced ligand-to-ligand charge transfer resulted in 67% of the photo-excited internal charge transferred from CN to the hydroxymethylamino group in MRF, whose amino group was the catalytic site for the CO2 photocatalytic reduction to CH3OH. This study provides a series of new metal-free photocatalyst designs and insights into the molecular-level structure-mediated photocatalytic response.


Assuntos
Dióxido de Carbono , Metanol , Catálise , Formaldeído , Grafite , Ligantes , Microesferas , Compostos de Nitrogênio , Polímeros , Resorcinóis , Triazinas
18.
Fish Shellfish Immunol ; 130: 332-341, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36115605

RESUMO

Grass carp (Ctenopharyngodon idella) is the largest economic fish in freshwater culture in China, which is predisposed to infectious diseases under high temperature. Under the background of global warming, the industrialization of the Pearl River Delta region has led to aggravated thermal pollution, which has increasingly serious impacts on the aquatic ecological environment. This will result in more frequent exposure of grass carp to overheated water temperatures. Previous studies have only identified the regulatory genes of fish that respond to pathogens or temperature stress, but the transcriptional response to both is unknown. In this study, the histopathological analysis showed heat stress exacerbated spleen damage induced by Aeromonas hydrophila. The transcriptional responses of the spleens from A. hydrophila lipopolysaccharide (LPS) -injected grass carp undergoing heat stress and at normal temperatures for 6, 24, and 72 h were investigated by mRNA and microRNA sequencing. We identified 28, 20, and 141 differentially expressed (DE) miRNAs and 126, 383, and 4841 DE mRNAs between the two groups after 6, 24, and 72 h, respectively. There were 67 DE genes mainly involved in the cytochrome P450 pathway, antioxidant defense, inflammatory response, pathogen recognition pathway, antigen processing and presentation, and the ubiquitin-proteasome system. There were 5 DE miRNAs involved in regulating apoptosis and inflammation. We further verified 17 DE mRNAs and 5 DE miRNAs using quantitative real-time PCR. Based on miRNAs and mRNAs analysis, continuous heat stress will affect the antibacterial responses of grass carp spleens, resulting in aggravation of spleen injury. Together, these results provide data for further understanding of the decreased tolerance of fish to pathogen infection in persistent high-temperature environments.


Assuntos
Carpas , Doenças dos Peixes , Infecções por Bactérias Gram-Negativas , MicroRNAs , Aeromonas hydrophila/fisiologia , Animais , Antibacterianos , Antioxidantes , Carpas/genética , Carpas/metabolismo , Proteínas de Peixes , Resposta ao Choque Térmico , Imunidade Inata/genética , Lipopolissacarídeos/farmacologia , MicroRNAs/genética , Complexo de Endopeptidases do Proteassoma , RNA Mensageiro/metabolismo , Ubiquitinas , Água
19.
Org Biomol Chem ; 20(44): 8605-8609, 2022 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-36300376

RESUMO

An efficient Cu-catalysed protoboration of allenyl-Bdans is presented. Under the optimized reaction conditions, a series of allenyl-Bdans reacted smoothly with B2Pin2 to afford ß-boryl allyl-Bdans in moderate to high yields with excellent regio- and stereoselectivity.


Assuntos
Cobre , Catálise
20.
Environ Sci Technol ; 56(12): 7696-7706, 2022 06 21.
Artigo em Inglês | MEDLINE | ID: mdl-35613430

RESUMO

An innovative strategy to control nitrogen oxide emission from flue gas was developed using the wet flue gas denitrification technology. The use of cyclodextrin (CD) as an additive facilitated NO2 absorption by the sulfite absorbent. Compared with absorption by a sulfite solution (59.12%), the instantaneous absorption efficiencies employing CD improved to 94.57%. Moreover, 48 h of continuous absorption indicated cyclic utilization of CD. The favorable role of CD was ascribed to facilitating the limiting step for the entire NO2 absorption-dissolution process which included both water solubility and gas-liquid mass transfer. Furthermore, we propose a potential mechanism of CD/sulfite mixed solution absorbing NO2, among which the favorable role of the additive is related to its amphiphilic behavior toward gas and liquid phases. Additionally, a kinetic model describing the rates of gas-liquid transfer and macro absorption was established based on various operating conditions. This model explains the absorption improvement in the kinetic aspect and provides theoretical guidance for practical applications.


Assuntos
Ciclodextrinas , Dióxido de Nitrogênio , Óxido Nítrico , Óxidos de Nitrogênio , Sulfitos
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